Intermag 1995 Held in San Antonio, Texas

Scientists and engineers from around the world gathered in San Antonio, Texas from April 18 to 21 at Intermag '95. The following summaries were prepared by the session chairs. The photos are courtesy of John Nyenhuis and Martin Sablik.

Session AA - MR Heads Symposium
By Ralph Simmins, Hewlett-Packard

Session AA was a symposium of four invited papers on MR head technology. The session covered a broad range of topics of interest to manufacturers and users of MR heads including all stages of MR head development. Whether you are shipping parts by the millions, shipping parts per million or spending millions per part, there was something in this session for you.

Paper AA-01, presented by Prof. N. Bertram of CMRR/UCSD, gave a series of analytic expressions for the output of an MR sensor or GMR (spin valve) sensor. The expressions included typical geometrical and material parameters so that the impact of design changes or processing changes can be easily estimated. It was shown that the area under the voltage pulse from an isolated transition can be used to evaluate changes in head parameters without requiring knowledge of head to media separation and media transition length parameter. The results of the model agree well with published data on MR and GMR heads.

Paper AA-02, presented by Dr. R. Fontana of IBM, described a method of comparing various types of thin film heads with regard to manufacturing. The complexity of typical photolithography and deposition steps used in making recording heads was described. By counting the number of these process steps, the manufacturing complexity of various thin film heads was compared. A state of the art three coil layer inductive thin film head requires 58 wafer process steps. A variety of SAL heads require a similar number of wafer process steps. A dual element MR head requires typically 6 to 8 more wafer process steps than the three layer inductive head. Comparing the fraction of processing attributable to the MR sensor part of a complete read/write device; a simple barber pole sensor accounts of 12% of the wafer processing, a SAL accounts for 15% to 20% and a dual element device is 25% to 30% of the wafer processing.

Paper AA-03, presented by Dr. T. Lin of IBM, compared the processing and properties of a few of the materials which have been used for exchange stabilization of MR sensors. The three materials considered are FeMn, NiMn and NiO. The conductive exchange layers are deposited on top of the NiFe MR film. The insulating NiO, however, is typically deposited first, followed by the NiFe MR and then the lead conductors. The critical parameters for the exchange materials are corrosion sensitivity, temperature sensitivity and the annealing requirements. The corrosion resistance of NiO is excellent, that of NiMn is similar to that of NiFe, and the FeMn corrosion resistance is poor. The blocking temperature of NiMn is above 400 C, NiO is approximately 200 C and FeMn is approximately 150 C. Only the NiMn requires annealing to achieve the desired properties. The conclusion was that all three of the materials are viable candidates to use for exchange stabilization of the MR sensors.

Paper AA-04 was withdrawn. Paper AA-05, presented by Dr. W. Folkers of Philips Research, described the design, characterization and modeling of a yoke type GMR head. The reason for pursuing a yoke type head is that the active GMR element is not exposed at the tape bearing surface so the GMR materials and exchange stabilization materials are recessed and protected. Finite element calculations were used to evaluate the magnetic performance of the device for various geometries and material properties. The design rules resulting from the evaluation included the requirement of high permeability of the free layer and no saturation at the center of the free layer. The completed heads were tested and compared to barber pole heads. The signal level for 10 micron track width GMR heads was ten times larger than the signal from a similar track width barber pole head. Since the resistance of the GMR element is greater than the barber pole element, the signal to head noise improvement is somewhat less than the factor of ten.

Session AB - Magnetic Thin Films I
By R. M. Walser, University of Texas at Austin

R. Jones et al. reported on the effect on magnetic properties due to RF diode sputtering thin NiFe films on sloping surfaces. With increasing tilt angle, the films were more isotropic, and exhibited at 90Ż rotation of the easy axis from the direction of an applied magnetic field. The rotation was independent of the sign of the magnetostriction, decreased with substrate bias, and was likely due to crystallite shape anisotropy.

The effect of sputtering conditions on the exchange fields and magnetic properties of CoNiO and CoNiO/NiFe thin films was examined by A. J. Devasahayam and M. Kyrder. Negative substrate bias, found to be the critical parameter for obtaining exchange fields in CoNiO films to 25 Oe (at -150V), promotes (111) texture in both NiFe and CoNiO. Increased Ar pressure reduced the exchange field. Y. K. Kim et al. investigated the effect of several parameters on the Hex of couples NiFe/FeMn films with thin NiFe layers. For NiFe underlayers thickness in the 30Ā200 Oe were obtained.

Field induced magnetic aniostropy, internal stress, and structural properties of electrodeposited bcc Fe-Mn alloy films were reported by K. Tanahashi et al. A maximum field induced easy axis anisotropy Ku ~104 erg/cc was obtained for films with 4.2 at% Mn where there is a transition from the bcc phase to a bcc-fcc mixture.

K. Okuyama et al. studied the microstructural properties of NiFe films deposited by extremely clean sputtering process (104 times improved). NiFe films were deposited by DC magnetron sputtering from ultra high purity targets in ultra pure process gases. A 2-3 fold increase in grain size was obtained for polycrystalline NiFe films deposited with base pressures of 10-11 to 10-12. A lamellar initial film growth mode was observed to replace the usual columnar structures.

Three papers reported on various aspects of laser-deposited thin films. Robin Kennedy reported on the growth of iron oxide, nickel oxide and cobalt oxide thin films by laser (Nd:YAG, 1=1064 nm/15nsec pulses/10 Hz) ablation of metal targets in molecular oxygen. Films on glass substrates were randomly oriented in the plane, but had a perpendicular oriented growth that depended on the growth rate. High quality c axis [100] Fe304 and NiO films grew on [100] LaA1O3, SrTiO3 and MgO crystalline substrates. Thick YIG films were produced by pulsed laser deposition for microwave device integration by H. Buhay et al. Films were deposited on GGG 111 substrate at 850C, and on Si substrates at 550 C followed by a RTA. The 9GHz FMR specturm of PLD films on GGG substrates had a linewidth (DH=5.7 Oe) about 5x that of single crystals. F.Huang et al. reported the successful PLD of hexagonal barium ferrite films on the (111) surface of large lattice constant garnet substrates. The film structure was highly sensitive to the oxygen pressure. Films grown at 800C in 180mT oxygen were crystallized with a perpendicular easy c-axis orientation, and had near bulk properties.

A new technique for quantitatively estimating the anisotropy dispersion in soft was reported by K. Ishiyama, et al. This technique utilizes a biaxial VSM. The use of this technique was demonstrated through independent estimates of the magnitude and angular dispersion of anisotropy from measurements on soft magnetic films. Polarization dependent EXAFS was used by J. E. Snyder to study the local anisotropic structure in amorphous Ba-Fe-O films and its role in determing magnetic anisotropy in crystallized Ba-hexaferrite films. Films, crystallized during deposition, or by post deposition annealing, showed a wide variation in anisotropy magnitude and direction not distinguishable by X ray and TEM. EXAFS data showed that the local structural anisotropy in the as-sputtered amorphous films determines crystal texturing during annealing.

A high conduction state was recovered by G. B. Turpin et al., in annealed ca- substituted YIG by applying a DC electric field at 300K. Annealeing at 1000C increased the resistivity from 103 to 107 W-cm, but subsequently reduced to 300 W cm in a field of band. O. Song and R. C. O’Handley studied anomalies in which the sign and magnitude of the magnetostriction of magnetic thin films are different than the bulk. Magnetostrictive coupling coefficients in NiFe/Ag/Si films were determined as a function of NiFe thickness. For t>40A the measured value is the same as in the bulk, but becomes strongly positive for smaller thicknesses. The anomalies are due to variations in microstructure and strain in ultrathin and thick films, and to the low symmetry of the surface.

Session: AC - GMR 1
By M.T. Kief, Dept. of Physics, University of Alabama

Session AC (GMR 1) was composed of about half papers on Colossal MagnetoResistance (CMR) manganeseńoxide based films and half papers on Giant MagnetoResistance (GMR) materials including Spinvalve and multilayer films. The pursuit of higher magnetoresistance values continues. The CMR materials lead the way with reports of MR values in NdSrMnO (AC-01) and LaCaMnO (AC-03) in the 106 % range using the inflated convention of MR%=[R(H=0)ńR(Hsat)]/R(Hsat). Optimal MR typically still means saturation fields in excess of 1 Tesla and temperatures well below room temperature. The highest MR values were shown in laser ablated samples but the precise relationship between structure and MR is unclear. AC-01 reported that their samples were very sensitive to preparation and annealing but only found a weak correlation between crystallinity and MR in their best samples.They suggested that the O2 concentration maybe more critical to the obtaining the highest MR. On the other hand, ACń03 suggested that the very largest MR may be directly related to lattice strain in the epitaxial thin film with a their best results in LaCaMnO near a lattice parameter of a=3.791A. In support of this, they reported a very interesting trend in MR vs. thickness which peaks near 1000?. Perhaps these two reports are not in disagreement. AC-05 reported on mixed phase samples which appeared to show shift in lattice constant with O2 annealing. Finally, encouraging results were shown for methods of preparation other than ablation. LaCaMnO samples prepared by facing target sputtering (AC02) showed MR around 500% in nonsaturating fields of 0.8T.

The portion of the session on thin film GMR materials was varied. A study of the macroscopic ferrimagnetic system Co-EuS was presented in AC-04. This granular-like system displays a negative MR of about 3% in 1 T at 295 K and switches to a positive MR at 4.2 K. AC-06 presented a study of exchange coupling in FeNi/Cu/FeNi/FeMn spin valves. They showed results consistent with pinholes in Cu layers <1.5nm and weak ferromagnetic coupling in Cu layers form 1.5nm to 3.5nm. Most interesting this weak ferromagnetic coupling region was well fit by Neel’s magnetostatic “orange-peel coupling” model. AC-07 investigated ferromagnetic coupling in NiFe/Co/Cu/Co/NiFe/FeMn spin valves and found the their best results for structures grown on single crystal MgO (001) with a 6.6% MR and less than 2 Oe ferromagnetic coupling field. AC-08 examined MBE grown Co/Cu (001) superlattices and found the MR to oscillate with Cu thickness. More surprising, they reported a correlation between the MR and an oscillatory 90 degree coupling and little 180 degree coupling. The authors suggested that this unusual coupling was due to interface roughness. AC-09 compared the coupling in Co/Cu(111) and Co92Ag8/Cu(111) MBE grown trilayers. The addition of Ag causes a disappearance of AFM coupling which is attributed to a phase shift in the bilinear exchange coupling.

Session AS - Magnetic Sensors I
By James M. Daughton, Nonvolatile Electronics, Inc.

The first 9 papers in this session concerned several very diverse topics including signal/noise ratios in permalloy magnetoresistive sensors, sensors using amorphous wires and ribbons, a mutual inductance senor using magnetostriction to measure torque in a steel shaft, and a nondestructive test for defects in conducting materials using eddy currents. Paper AS-02 (Bushida et al.) demonstrated a very sensitive field sensor using amorphous wire and the magneto-impedance effect in a circuit using a Colpitts oscillator. Paper AS-03 (Kito et al.) demonstrated an excellent low field linear sensor using twisted amorphous wires. Paper AS-05 (Nderu et al.) studied the relationship between stress and the magnetic characteristics of amorphous wires. The torque detection scheme in paper AS-06 (Koga and Sasda) used a figure 8 coil scheme with ferrite materials to measure torque in a carburized steel shaft using the change of mutual inductance between coils with torque in the shaft. Paper AS-08 (Sasada and Watanabe) used an array of eddy current sensors for nondestructive detection of flaws in conducting sheets. Paper AS-09 (Abe and Matsushita) studied a technique for magnetic pulse propagation in amorphous wires which shows promise for precision position sensing.

Session BC - Thin Film Media I
By E.M.T. Velu, Data Storage Systems Centers Electrical and Computer Engineering Carngie Mellon, University Pittsburgh, PA 15213

This session had twelve contributed papers. Five were on CoCrPt, CoCrTa and CoPt media, three were on Barium ferrite media, two were on SmCo thin films and the last two dealt with CoCr based perpendicular media. Novel underlayers, precoat layers, substrate roughness and new and alternative materials for recording were topics covered in this session.

The use of an NiAl underlayer (BC-01) in combination with a thin Cr (25 A) intermediate layer was reported to bring about an increase in coercivity and a reduction in grain size for CoCrPt thin films containing 18 at.% Pt. An increase in coercivity of about 1000 Oe was attributed, to the presence of strong (10.0) hcp cobalt texture caused by the room temperature (110) texture of NiAl, and to an interfacial chemistry caused by the Cr intermediate layer. A maximum coercivity of 3500 Oe was reported for 30 nm thick CoCrPt films.

An aluminum precoat (BC-02) layer deposited at 280 C on glass diffused into a Cr underlayer expanded its lattice giving rise to better lattice match between Cr (110) and CoCrTa (10.1) planes. This increased the coercivity by 300 Oe to a maximum of 1400 Oe. Also, aluminum microbumps reduced stiction. Out of Cr, W, Zr and Ta precoat layers (BC-03) deposited at 250 C on glass disk substrates, only Ta led to a strong (200) texture for CoTi (15 at.% Ti) underlayer. This texture gave better epitaxy with (11.0) CoCrPt and helped to achieve low medium noise and high output signal at 150 kfci linear density. CoCrTa and CoCrTaPt media (BC-04) were studied on NiP/Al and glass substrates with and without texture (mechanical). The authors report that a higher coercivity and a lower medium noise were obtained on textured NiP/Al substrates than on glass substrates.

CoPt and FePt ordered phases (Llo type) were new high anisotropy materials reported (BC-05) for ultrahigh density recording. As deposited CoPt (50 at.%) films had f.c.c. structure and low coercivity. On annealing at 700 C at tetragonal Llo phase developed with c-axis at 36° to the film plane. The coercivity exceeded 10 kOe for 2 nm size grains. CoPt films co-sputtered with ZrO2 showed a smaller grain size even after annealing. Disks were fabricated with these films and recording properties were reported. High resolution TEM microstructure (BC-06) of SmCo/Cr films revealed an amorphous matrix with 5 nm size crystallites. The crystallites had more than one stacking mode with ABC (fcc), AB (hcp) and random stacking with multiple layers. The Sm content of the crystallites was lower than that of the amorphous matrix.

Magnetic switching volume (BC-07) and viscosity coefficients were also reported for SmCo and SmCo/Cr films.

Effects of grain alignment on medium noise of longitudinal Ba-ferrite media were studied by micromagnetic modeling (BC-08). Films with stacks across the track direction showed higher medium noise than films with random stacks or stacks along tracks. Barium ferrite (BaFe11.4(Ti,Zn)0.3O19) films (BC-09) deposited at 640 C on silicon nitrite coated carbon substrates were crystalline with in plane aniostropy. For a disk with a coercivity of 2100 Oe a D50 of slightly over 100 kfci, a PW50 of 0.35 Ķm, an overwrite of 30 dB and an SNR of 29 dB at 150 kfci were reported when tested at a fly height of 3.5 Ķin. In another paper (BC-10) the effect of substrates, oxygen pressure and growth temperature were reported to obtain c-axis in-plane oriented crystalline Ba-ferrite films by laser ablation deposition.

Preparation conditions, magnetic and recording properties were reported for CoCrTaPt (BC-11) perpendicular media. An addition of 10 at.% Pt to Co78Cr17Ta5 was claimed to significantly increase the perpendicular coercivity of CoCrTa films from 2600 Oe to 3400 Oe. The use of thinner (55 nm) CoCrTaPt films increased the track average amplitude signal by 45% and decreased the PW50 by 10% over thicker (75 nm) CoCTa media. High coercivity CoCr films (2000 Oe) with perpendicular anisotrophy were prepared (BC-12) at room temperature sputtering as a result of nitrogen gas addition.

Session BE - Magnetic Multilayers and Ultra Thin Films I
By T. Suzuki, IBM Almaden Res. Center/ToyotaTech. Institute

The session included one invited and nine contributed talks. The invited talk by Engel (U. Arizona) on the evolution of the perpendicular magnetic anisotropy in X/Co/Y (X, Y: Ag, Au, Co and Pd) with an overlayer thickness X provided very informative results on the role of the interface between Co and X, Y in the anisotropy mechanism. Also shown was the effect of a capping layer on top of X/Co/Y; a 2 A thick Co capping layer significantly decreased the perpendicular anisotropy of Cu(111)/10Ā Co/4.8 A Au, whereas no effect of a capping layer of 2.4 A Au on the anisotropy was observed in Cu(111)/10A Co/4A Cu.

Suzuki (IBM) reported the coercivity mechanism of (Co/Pt) and (Co/Pd) multilayers in conjunction with microstructure. The discussion was made on the basis of micromagnetic phenomenological models and also of a relaxation mechanism. The change of Barkhausen volume (10-18cm3) with a number of layers in (Co/Pt) was found to correspond to its trend of Hc.

The magnetocrystalline anisotropy calculation in (Pt/Co/Pt)/X multilayers (X=Pd, Ag or Cu) was presented by Mac Laren (Tulane U.). The calculation was made very extensively for the systems with different layer thicknesses, and the discussion was made on the individual atomic contribution to the total anisotropy.

Bennett (NIST) presented an observation method of quasi-dynamic magnetization process. The technique was claimed to be useful for nondestructive characterization of the defect structure as well. An example of the observation of the magnetization reversal in (CoNiCu/Cu) with GMR effect was presented.

Mendik (Colorado State U.) presented a work of spin wave excitations of Brillouin light scattering (BLS) in Fe/Cr/Fe single crystal sandwich film grown on a (100) GaAs. The work reported the BLS for the scattering configuration with K and H parallel. For this geometry, three modes, namely the primary stokes, anti-stokes and a third Stokes mode which appears in the cross over range were observed.

Lafford (U. Sheffield) discussed phenomenologically the saturation magnetostriction of FeCo/Ag and CoPd/Ag. A model was developed by taking into account the contribution of an interface to the volume average saturation magnetostriction, which leads to a way of estimating the interface effect without any assumption of the magnetostrictive properties of the constituent layers.

M. Chen (Colorado State U.) presented a very extensive study of the characteristic dispersion relations of frequency vs. in-plane wave number k for the various dipole- exchange spin wave modes for a 1 Ķm thick YIG film. Two different methods to calculate the dispersion relations, namely the scalar potential and Green’s function approaches. Dispersion curve calculations were carried out for the various field and propagation direction combinations for the film.

Session: BT - Microwave Materials
By Craig A. Grimes, University of Kentucky

Okamura et al. described a high frequency magnetic device to determine the conductivity of an aqueous solution. Operating at approximately 2.7 GHz, a magneto- static surface wave is launched between two YIG couplers. The attenuation of the coupled wave is dependent upon the conductivity of the non-magnetic solution between the two YIG couplers. The theory they developed to describe coupling as a function of solution conductivity fits rather impressively with experimental results. Tanno et al. reported on the drift of the magnetic resonance field as a function of temperature and demagnetizing field (sample aspect ratio) in Bi and Ga substituted epitaxially grown YIG films. They find that samples with lower values of growth induced anisotropy are less susceptible to changes in the resonance frequency with temperature. Nedkov et al. describe a highly anisotropic BaFeScO and BaFeInO hexaferrites that are highly absorbing in the 20 to 30 GHz region.

Doresey et al. examined the magnetic properties of pulse laser deposited MnZn ferrite films as a function of film composition with the objective to reduce the magnetocrystalline anisotropy of the films. By increasing the ZnO content in the MnZn ferrites softer magnetic properties were obtained. Kabos et al. investigated the threshold power input required to induce spin wave instability in thin YIG films as a function of biasing magnetic field strength. Measuring the critical angles for Brillouin light scattering the were able to determine the k-based distributions of the excited magnons. Their results indicate a wide discrepancy between bulk theory and thin film experiments. Sun and Chen presented a theoretical study of microwave propagation of microstrip lines atop YIG substrates. Dispersion and cutoff frequencies were determined as a function of YIG substrate thickness, and width and spacing of the microstrip lines. It is found that thicker YIG substrates greatly increase dispersion of the propagating wave.

Session CA - M-O High Density Recording Symposium
By T. Suzuki, IBM Almaden Res. Center/Toyota Tech. Institute

The symposium had five invited speakers for high density magnetooptical recording. Three talks were primarily on land/groove recording with MSR (Magnetically induced Super Resolution) one on the overview of achieving 10X high density recording and one on blue-green laser.

Birukawa (MEI) reported land/groove recording with MSR at 680 nm. Emphasis was made on the effect of groove depth on recording performance. A shallow groove depth (~46 nm) was found to be suitable for MSR and land/groove high density recording. Also found was the double mask type MSR to be effective in reducing cross- talk and cross-erasing.

Murakami (Sharp) presented the performance of MSR with CAD (Center Aperture Detection) scheme, and demonstrated the areal density 2.2 Gbit/in2 at 680 nm. The cross-talk cancellation was discussed for both magnetic field modulation and light intensity modulation methods.

Iwanaga (NEC) discussed the result of land/groove recording with a cross-talk canceller technique. He demonstrated the high density recording (>10X) with cross-talk canceller and a 3-level Viterbi scheme.

Cheng (IBM) presented an extensive approach to perform 10X recording, where primary techniques including short wave lengths, high numerical aperture and the reduction of track pitch were discussed in detail.

Baude (3M) reviewed the current status of II-IV blue-green laser for optical storage application: threshold current <500 A/cm2, threshold voltage <3.8 volt, peak pulsed power >500 mW and CW life time >2 hr at 300 K. He extended the view for future technolocial developments of blue-green lasers, which was very informative for optical storage.

Session CC - Head/Media Interface: Media & Characterization
By Richard L. White, SSD IBM Corp.

Session CC (Head/Media Interface: Materials and Characterization) dealt with an impressive breath of topics under the general umbrella of head/media tribology. The papers could be roughly divided into three groups. The first group of papers discussed either the performance, characterization, or lubrication of primarily carbon based thin films used in both heads and disks. Paper CC-01 presented data showing improved performance in carbon overcoats as the hydrogenation was increased. Head disk interaction was monitored with a novel high resolution optical technique which demonstrated differences in lube depletion within the CSS track as the film hydrogenation was changed. Paper CC-02 described techniques which were used to generate and characterize lubricant layers with a comb type structure. These pseudo 2D hydrogen bonded networks were created with two type of lubricants, R1COOH and R2NH2. Paper CC-03 described an electrical I/V measurement technique which could be used to characterize highly resistive overcoats.

Two other papers in this general group described the use of carbon based thin films as protective layers on head air bearing surfaces and as basecoats in head fabrication. Paper CC-04 compared the tribology performance of uncoated sliders, carbon coated sliders and nitrogenated carbon coated sliders. The latter were superior. Paper CC- 05 described the use of diamond-like carbon as a basecoat material. They found that after lapping, these materials can protrude above the air-bearing surface plane and degrade the slider tribology performance. The final paper in this group CC-06 treated the subject of barium ferrite tribology. Large gain size yielded disks with unacceptably high take-off height. Dopants (Ti and Co) which reduce grain size and improve tribology, unacceptably also reduce coercivity.

The second group of papers described work on alternate substrates. Paper CC-07 described the excellent contact start-stop performance and shock resistance that could be obtained with a new lithium disilicate glass-ceramic material. Paper CC-08 described a novel catalytic oxidation technique which could be used to texture an amorphous carbon substrate.

The last group of papers dealt with the tribology of magnetic tapes. Papers CC-09 and CC-10 were presented together. That work described the mechanical properties of a number of alternatives to the industry standard PET and found a number of alternatives which provide superior characteristics. In paper CC-11 superior corrosion performance was obtained with an obliquely deposited Co-O thin film with a diamond-like carbon protective layer. Paper CC-12 likewise found the corrosion resistance of tapes could be improved by the use of protective layers, although they investigated SiOx overcoats.

Session: ED - HEAD/MEDIA INTERFACE: MECHANICS/SURFACE MODIFICATION
By David B Bogy, Department of Mechanical Engineering, U.C. Berkeley

This session was attended by more than 100 persons, and all 12 papers were presented. The first two papers dealt with disk texturing processes needed to permit ultra- smooth disks to be used without encountering the well-known stiction problem. The invited paper by P. Baumgart presented a novel laser texturing method that is already being implemented in some IBM drives. The paper focused on the method, the parameters and the results and did not say much about the tradeoffs. The second paper presented a method to measure and characterize disk texture in the transition zone of zone textured disks. This is another approach for dealing with the stiction problem on ultra-smooth disks. Paper 07 also was concerned with the stiction problem, but the solution here was to have small “feet” on the slider so that it cannot come into sticking contact when is rests on the disk in the presence of a lubricant.

Another series of papers was concerned with air bearing design for very low flying sliders. ED-03 presented a 25 nm slider design and discussed the air bearing design program developed at UC Berkeley in the Computer Mechanics Laboratory. Paper ED-04 was a follow-on that presented an design optimization program and demonstrated its use for TPC and shaped rail negative pressure sliders. ED-05 was also an air bearing design paper that focused on the inclusion of etch wall angle in the design process.

ED-06 presented a particular slider designed for a semi-contact, and discussed the various issues associated with that approach. Finally ED-08 was on a different topic, that of achieving high track density through a micro actuator fabricated by silicon micro- machining methods.

This session was lively and showed that interest remains high in solving the problems associated with achieving the low slider-disk spacings needed for the industry to advance to the next level of storage density. The papers were generally of high quality and the speakers gave well-prepared presentations.

Session EQ - Hard Magnets By V. Panchanathan, Magnequench, Delphi (E), Division of GM, Anderson, IN 46013 USA

The papers in this session dealt with basic studies and applications of hard magnets by authors from different countries. Von Staa et al. discussed energy dissipation in MQ3 magnets and concluded that a determination of the anisotropy field strength from the damping time curve of MQ3 magnets was possible. Biaxial stress effects on magnetization perpendicular to the stress plane was studied using model studies by Sablik et al. The model results were also compared with the experimental results. Iida et al. studied the use of Sm2Co17 magnets for the control rod mechanism for nuclear reactors after proper surface treatment. Kim et al. studied the role of oxygen in sintered (Nd,Dy)(Fe,Co)B magnets and reported proper oxygen addition improved the thermal stability of these magnets. Chang et al. reported a relationship between hydrogenation process and corrosion behavior of cast and sintered NdFeB alloys of different volume fraction of Nd rich phases obtained by varying the TRE contents. The electronic structure of Fe16N2 was studied by He et al. using a generalized gradient approximation. Using neutron diffraction studies Hu et al. studied the variation of unit cell volume in ErNi(5- x)Cox alloys and reported that an easy magnetization direction was along the c axis. Anamalous thermal expansion studies in Nd-Fe-(Si,Al) systems were carried out by Zhang et al. to get insight into the differing site preferences in Al and Si in 2-17 structure.

Session ER - Soft Magnetic Materials (Not Recording)
By Bob O'Handley, M.I.T.

All sixteen posters accepted in this session were presented. There were six papers related to power loss and to Barkhausen noise, three on magnetic circuits and motors, two on magnetic anisotropy dispersion characterization, two on magneto-elastic effects, two on planar inductors, and one on thin permalloy films.

The effect of a transverse bias field on the domain wall stability in thin permalloy films was studied (ER-3) and the results were applied to understanding the Barkhausen noise in thin film fluxigate magnetometers (ER-6). The nature of the Barkhausen noise in steel was found to be strongly dependent on the type and distribution of microstructural features, finer grain size giving smaller and more numerous Barkhausen pulses (ER-7). The hysteresis component of power loss in Ni-Zn ferrites was reported to be higher for sinusoidal voltage conditions than for rectangular voltage conditions (ER-8). An eddy current model was used to study the loss in Si steel and it was found that the eddy current contribution to Hc increases as (dB/dt)n with n Ň 0.6 (n=1 is the classical result) (ER-9). The eddy current loss in Mn-Zn was studied near a K1 minimum at 353 K and found to vary as f 2Bm2/r (ER-10). A method of calculating iron-loss characteristics was described and applied to an orthogonal core transformer (ER-15).

A model for a nonlinear conductive magnetic circuit was described and applied to the performance of a current-sensing fault detector (ER-11). The model was integrated with a similuator to solve electrical coupling problems (ER-12). The magnetic circuit of a multilayer ferrite chip inductor was successfully modeled by a 3-D finite element method (ER-13). The reduced eddy-current benefits of using iron powder pole faces for MRI magnets was analyzed by eddy current modeling (ER-14). A planar motor/actuator exhibiting high force, high speed and submicron position sensitivity was realized by using permendur flux concentrators on a ferrite base (ER-16).

The departure from Stoner-Wohlfarth theory of the hard axis permeability of magnetic thin films at high frequencies was related to dispersion in the anisotropy (ER- 1). Poster ER-5 showed by rotational magnetization measurements that while very well defined, easy axes exist in grain oriented Si steels, the magnetization is not isotopic in non-oriented steels. A method of fitting magneto-elastic resonance curves to give improved values for more parameters than simply k33 was described in poster ER-2. The effect on magnetomechanical properties of composition variations to achieve compensation in the second anisotropy coefficient (K2 = 0) in Tbx Dyy Hoz Fe2 (x + y + z = 1) were reported (ER-4).

Session: FA - Thin Film Medium Symposium
By Neal Bertram, UCSD-CMRR

The purpose of this session was to discuss relative merits of oriented versus non- oriented (isotopic) thin film media. There were four invited papers and the session was extremely well attended. All speakers agreed that the philosophy of disc making is to have good squareness in order to write sharp transitions with low DC noise, as well as the other attendant properties of low transition noise, good overwrite and acceptable edge track behavior. Two means of achieving this is by circumferentially orienting the media, or by preparing isotopic media. In the first case, texturing can lead to a superlinear increase in noise at high recording densities, but high squareness is achieved. In the latter case isotopic media will give desired track uniformity, but might result in low squareness.In addition, circumferential texturing creates an inevitable surface roughness. The elimination of scratches to produce super-smooth media results in isotopic magnetic properties.

The first paper (FA-01) by Ken Johnson (IBM) was a review of orientation techniques in thin film media. He discussed how in line sputtering yields “twice around” modulation and argued that circumferential texturing is essential to reduce signal as well as noise modulation. He believes as well as the speaker for FA-02 that stress is the mechanism for induced anisotropy for circumferential texturing. The evidence was that disc signal modulation was coherent between the top and bottom film surfaces.

FA-02 was a paper by Tu Chen and coworkers (KOMAG) discussing relative merits of oriented and isotopic media. He emphasized the role of stress in thin film media due to texturing and argued that if the grains are physically isolated, stress may not be transmitted. However, he argued that isotopic media can be prepared with high squareness and low noise, at least for inductive heads, with no intergranular exchange between grains and a 3D random crystallographic orientation. Well segregated grains will result in reduced stress, even if the magnetostriction coefficient is not zero.

FA-03 was a theoretical paper by Jian-Gang Zhu (U of MN, MINT) which discussed the SNR behavior of various microstructures. He argued that an isotopic medium consisting of a “pure bicrystal” structure with no exchange between the sub crystallites and moderate exchange between the larger bicrystal grains would satisfy the requirement of good SNR and high squareness.

The last paper in this session, FA-04, by Mary Doerner and co-workers (IBM, Stanford, CMRR-UCSD) discussed the preparation of media for ultra high density recording utilizing super smooth substrates. To achieve good squareness, in-plane anisotropy is achieved by proper Cr underlayer growth morphology. This results in a bicrystal structure that yields high squareness and low noise. TEM analysis showed a distribution of relative areas in each bicrystal that reduced the inherent high anisotropy of CoPtCr to yield acceptable coercivities. She argued that this structure gave an effective distribution of grain anisotropy magnitudes that reduced the effect of a small intergranular exchange, which would normally yield unacceptable noise. She concluded by emphasizing the need for super smooth media that yields low modulation noise and minimal defect drop outs.

The overall conclusion of all speakers is that future media requires super smooth substrates and isotopic media.

Session: FB - Recording Systems II
By Rick Barndt

The first five of the ten papers in this session deal with performance comparisons/analysis of various advanced channels. Several papers expand on the sampled amplitude margin (or some similar statistic) technique for evaluating the performance of sequence detectors under various forms of channel degradations. These measurements aid in optimizing the total drive design and predicting yields, just as window and amplitude margins do in a peak detection channel. Two other papers tackle the complex tasks of analyzing the performance of the RAM-RSE and DFE with FDTS including the effects of error propagation. In the case of the RAM-RSE, the benefit of using local (in the trellis) feedback over global feedback is analyzed.

The latter five papers in the session offer more variety. In FB-06, the sampled amplitude margin performance metric is used to optimize the choice of read head width with other parameters fixed. Paper FB-07 is a study of the sensitivity of a PRML channel to inductive head parameter variations. The analysis presented in FB-08 regarding the nonlinear effects caused by write current baseline wander should be useful to DVCR (with 24/25 code) designers among others. In FB-09 a method for choosing the bias current in a SAL head to optimize the tracking signal is described. Finally, in FB-10 servo loop compensation for pivot friction is modeled and simulated.

Session: FD - Microwave II
By Douglas Adams

FD01 HIGH POWER EFFECTS IN THE COLLINEAR MAGNETOSTATIC WAVE OPTICAL INTERACTION, Anil Prabhakar and Daniel D. Stancil, Carnegie Mellon University, Pittsburgh PA.

Operation of efficient MO devices such as microwave filters and optical frequency shifters, require operation at high microwave power levels. Experimental results, however, show a significant broadening in the device bandwidth which cannot be explained by the simple first order limiting process. The authors discussed modeling of the interaction,including the effects of MSW attenuation and demonstrated that it was the major cause of observed frequency spreading. This work suggests that narrow band MO devices will require special microwave transducers which ensure a constant microwave field amplitude along the MO interaction length.

FD02 TEMPERATURE DEPENDENCE OF SPIN-WAVE AUTO-OSCILLATIONS IN Scń SUBSTITUTED YTTRIUM IRON GARNET FILMS, G. Srinivasan and A. N. Slavin, Oakland University, Rochester MI.

Investigation of the temperature dependence of the autońoscillation frequency in Sc-YIG films under parallel pumping showed reasonable quantitative agreement with previously described theory. It was expected that, if a weak temperature dependence of the relaxation parameter is measured and taken into account, the agreement between theory and experiment will be even better.

FD03 A RECIPROCAL MICROSTRIP PHASE SHIFTER, Chin Soon Teoh and Lionel E. Davies, UMIST, Manchester, UK.

Finite element method calculations of slot line and microstrip ferrite phase shifters showed that microstrip provides close to three times greater phase shift per unit length than slot line with identical dimensions and parameters. This work is of interest in the development of planar phase shifters and distributed circulators. The calculated difference in phase shift between microstrip and slot line is to be expected because of the difference between the microwave magnetic field patterns in the two transmission lines.

FD04 MAGNETICALLY TUNABLE SUPERCONDUCTING FILTERS USING YTTRIUM IRON GARNET FILMS, Makoto Tsutsumi, Takesh Fukusako and Hitoshi Shimasaki, Kyoto Institute of Technology, Japan.

Magnetically tunable superconducting microwave filters were fabricated from end coupled, half wavelength, YBCO microstrip resonators formed on MgO substrates which were formed into sandwich structure with YIG films deposited on GGG. Magnetic field tunability of 400MHz centered at 6GHz was measured. Loaded Q measurements on the resonators, which were undercoupled, showed values of less than 500. This low value was attributed to an increased fmr linewidth of the YIG at low temperatures due to fast relaxing rare earth impurities or, which is more likely, due to the increased loss in the GGG substrate due to the paramagnetic Gd ion.

FD05 RECOIL MAGNETIZATION IN PATRTIALLY ORIENTED HEXAFERRITES, E. Schloemann, P. J. Maher, Raytheon Research Division and J. A. Weiss, MIT lincoln Laboratories. FD11 MATHEMATICAL MODEL OF PARTIALLY ORIENTED POLYCRYSTALLINE HEXAFERRITE, E. Schloemann.

Measurements of the magnetization of several polycrystalline hexaferrites (FD05) were compared with a theoretical model (FD11) which allows for misalignment of the grain axes relative to an orientation axis. Methods for extracting the saturation magnetization, anisotropy field and maximum misalignment angle from the experimental data were described. The observed magnetization vs field dependence was shown to agree with the theoretical model when allowance was made for the distribution of misalignment angle, crystalline anisotropy, and porosity. This improved understanding of the magnetization behaviour is important in the development of optimum materials for self biased mmwave circulators.

FD06 ANTENNA ARRAY OF CIRCULAR PATCHES ON FERRITE SUBSTRATE, Hoton How, Ta-Ming Fan, Wei Liu and Carmine Vittoria. Was not presented.

FD07 DIRECT MEASUREMENT OF OCTAHEDRAL AND TETRAHEDRAL SITE ENVIRONMENT IN NiZn FERRITES, V. G. Harris and N. C. Koon, NRL, C. M. Williams, Morgan State University, Baltimore Md, Q. Zhang and M. Abe, Tokyo Institute of Technology, J. P. Kirkland, Sachs Freeman and Associates, Inc, Landover Md, and D. A. McKeown, Howard University, Washington DC.

Application of the EXAFS - Extended X-ray Absorption Fine Structure - technique to measure the local environment of transition metal ions in NiZn ferrite films formed by spin spray was demonstrated. This technique enables the distribution of cations and their valency in the crystal sites to be determined. Further application of this technique may lead to an explanation for the high tan delta measured in spin spray films which presently preclude their application in microwave devices.

FD08 COUPLED MAGNETOSTATIC VOLUME WAVE STRAIGHT EDGE RESONATORS FOR MULTI POLE MICROWAVE FILTERING, R. Marcelli, M. Rossi and P. De Gasperis, CNR, Rome, Italy.

FMR measurements performed on a pair of parallel coplanar straight edge YIG film resonators show that a lamda,m,n/4 seperation between the resonators results in optimum coupling for a two pole filter response. Lamda,m,n is the wavelength of the uncoupled magnetostatic wave resonator modes. Additional measurements in a microstrip format are desirable to verify the applicability of this result, obtained in a TE102 X-band cavity, to practical filter design.

FD09 SUBSIDIARY ABSORPTION SPIN WAVE INSTABILITY BUTTERFLY CURVE SIZE EFFECTS AND LATERAL MODES IN YTTRIUM IRON GARNET FILMS, G. Weiss, P. Kabos and C. Patton, Colorado State University, Fort Collins, CO.

Excellent agreement was obtained between experimental results and a theory of subsidiary absorption butterfly curves for YIG thin films. Inclusion of the lateral mode spacing results in an angular dependence for the spin wavenumber which replace the ad. hoc. dependence used in earlier theories.

FD10 INFLUENCE OF THE CARRIER SIGNAL PHASE ON THE FORMATION OF DARKSPIN WAVE ENVELOPE SOLITONS IN MAGNETIC FILMS, A. Slavin, Oakland University, Rochester, MI.

Previous experimental results have shown the existance of “dark” spin wave solitons in YIG films. Analysis presented here suggest that a 180 degree phase shift is necessary in the centre of the input “dark” pulse to yield soliton propagation. Since previous dark soliton measurements did not deliberately introduce a 180 degree phase shift it would be of interest to verify this theoretical prediction through additional experiments.

FD11 MICROWAVE NONRECIPROCITY IN MAGNETOELECTRIC CRYSTALS, C. M. Crowne, Code 6850.3, Microwave Technology Branch, Naval Research Lab. Washington, DC.

Antiferromagnetic crystals and crystals with expected simultaneous ferroelectric and antiferroelectric or antiferroelectric and antiferromagnetic properties, which display the magnetoelectric effect were shown to theoretically to posses the fundamental property of nonreciprocal propogation of electromagnetic waves.Some materials were suggested in which this effect should be observed and accurate data obtained.

Session HB - Inductive Heads
By Edgar M. Williams, Read-Rite Corp.

This session, containing ten papers (one invited), emphasized improvements in dynamic response and magnetic properties of inductive heads for use at high areal densities. Takano et al.(HB-01) showed experimentally that high resistivity thin film heads with Bs = 1.3T gave excellent high frequency (100 MHz) write characteristics, where low resistivity heads with Bs = 1.7T produced degraded high frequency behavior. Low resistivity films suffered from recording field phase delay and intensity reduction, while high Bs films with low resistivity improved field intensity without reducing phase delay. An important clarification in this paper was the necessity of reducing write field phase lags arising from eddy currents. Klaassen and van Peppen (HB-02) studied the time dependency of magnetic reversals in thin film head yokes and found a flux delay of about 420 ps presumably arising from gyro-magnetic effects. They recommended yoke lamination or high resistivity materials for improving head response time. Takahashi et el. (HB-05) discussed permeability measurements at 10 MHz for NiFe strips at widths between 1 and 200 microns; the films were NiFe/Ti/NiFe sandwiches with NiFe thicknesses between 10 and 30 nm and Ti thicknesses from 2 to 5 nm. They found that permeabilities of about 1500 could be obtained for strips as narrow as 2 microns and claimed there were applications to perpendicular recording heads in the 5-10 Gbits/sq.in. range.

Nishida et al.(HB-03) prepared FeTaN thin film heads with Bs = 1.6T deposited by DC magnetron sputtering; the heads required annealing at 500ŻC in a magnetic field, thus SiO2 insulation was used to withstand the annealing process. When tested on 3000 Oe thin film media, writing and reading behavior was superior to conventional NiFe heads. Inturi and Barnard (HB-04) studied the effect of nitrogen in FeTaN films under a variety of sputtering conditions. Film Bs was about 2.0T and showed little sensitivity to the nitrogen content; saturation magnetostriction increased linearly from -1.03x10-6 to +10-5 for nitrogen between 0 and 5 at%. Film coercivity was essentially constant (1 Oe) between 1 at% and 3.8 at % nitrogen; outside this range Hc increased rapidly.

Yoda et al. (HB-06) discussed fabrication of narrow track widths (1-8 microns) by low pressure collimation sputtering of NiFe and CoZrNb films to fill trenches in sputter- deposited SiOx films. CoZrNb film coercivities were unacceptable at useful levels of bias power, but the NiFe stripes had good morphology and low Hc.

Ogawa et al.(HB-07) presented on a three-layer coil thin film head for VCR applications. To give the required contact wear life on metal evaporated video tape, the gap depth (throat height) and pole thickness were increased to about 15 to 10 microns, respectively. Writing and reading behavior was superior to commercially available MIG heads used in VCR applications. Takayama et al.(HB-08) discussed a hybrid MIG head with a thin film helical coil of 42 turns formed on an alumina substrate with a NiFe core (180 um x 300 um x 10 um). Coil resistance was 22 ohms and inductance (1 Mhz) was 2.0 microhenries (1.15 nH/turn2). Bain et al.(HB-09) described a novel approach to tape head design where magnetic field and power dissipation require equal attention. Their thermally constrained transmission line model allowed tradeoffs between material permeability and heat sinking to achieve useful head designs. Karasawa et al.(HB-10) closed the session with a paper discussing experiments with a ring-type parametric read head connected to a varactor diode bridge and demodulator. Initially, the DC bias field (required for readback) was sufficient to erase the recording medium. This problem was solved by fabricating a toroidal head structure (NiZn ferrite) containing a partial gap (a ditch cut into the toroid.)

Session HD - Particulate Recording Media
By M. P. Sharrock, 3M

The session on particulate recording media demonstrated the continued vitality of this field. A paper from Sony discussed the use of very thin metal particle (MP) coatings, down to 0.15 micron thickness, similar to those described by Fuji in an earlier symposium in this Conference. Compared to conventional thicknesses, this construction gives moderately improved output at high recording densities, and markedly improved overwrite at intermediate densities. There were two papers dealing with magnetic time dependence. One, from the University of Alabama, described the dependence of coercivity on field-exposure time. Samples with pronounced thermally-assisted time dependence showed consistent behavior over twelve decades of time, down to the nanosecond range. Other samples showed two mechanisms, a rapid dependence in the nanosecond range and a slower one at longer times. The other paper, from the Jordan University of Women and the University of Western Australia, described a method for analyzing constant-field time effects without influence due to past magnetic history (field scan rate). There were three modeling papers. The first, from Univ. of Cal., San Diego, and Storage Tech Corp., was a simulation of overwrite in thick media. The second, from 3M, correlated noise with experimental measures of magnetic interactions in barium ferrite media. The third, from the University of Wales and 3M, was an analysis of orientation and magnetic interaction parameters, also in barium ferrite media. A report from the University of Alabama showed how the DIMAG technique (essentially AC susceptibility as influenced by transverse DC field) can be used to characterize the quality of magnetic particle dispersions. The predictions of the vector Preisach model for rotational remanence were verified in an experimental study from George Washington University. Preisach-type particles were studied experimentally in a structured garnet film in a paper from workers at George Washington University and the Research Institute for Materials Science (Budapest); coercivity and switching-field distribution were studied as a function of temperature. Particles of partially barium ferrite and partially metallic composition were characterized as to anisotropy and damping constant by FMR work at the University of Alabama and Hitachi Maxell. A paper from the National Tsing Hua University and the National Taiwan University discussed efforts to optimize the preparation of metallic particles (MP) by surface treatment with SiO2.

Session HP-02 - Recording Systems III
By Will Bliss, Cirrus Logic Colorado

The poster session covered a wide range of topics in magnetic recording including code construction, detector design, theoretical performance analysis, and exotic futures. A large crowd was attracted from open to close, exhausting the presenters who stayed over three hours. The poster format was highly successful, in that orders of magnitude more questions were asked (and answered) than in any “lecture session.” The close confines of the poster session hall also seemed to spark much more interaction between colleagues and competitors than the relatively sparse and cold lecture halls.

Session JE - Finite Elements & Optimization
By Adalbert Konrad, University of Toronto, Dept. of ECE

This session on Finite Elements & Optimization comprised 12 papers of which only one (JE-07) has not been presented. However, an unusually high percentage (36%) of the remaining 11 papers were presented by persons who were not listed as authors or co-authors. One would only hope that this phenomenon is not going to continue on a larger scale in the future.

Despite the fact that this was one of the last sessions of the conference on a Friday afternoon, the attendance was satisfactory. Obviously, the topic was of interest to a group of about 25-30 people who stayed until the very end of the session. Highlights of the session are described below.

K. Davey (American MAGLEV, Inc., Edgewater, FL) presented a practical approach to optimum magnet cross-section design for high speed magnetically levitated trains. The effectiveness of his approach depends on the derivation of a smooth, differentiable function of the performance index defining the problem. To this end, his technique is to use polynomials involving products of the key parameters. (Paper JE-02)

M. Juds (Eaton Corp., Milwaukee, WI) described the application of a coupled electromagnetic/structural finite element formulation to the analysis of an ac current relay contactor. The analysis included the effects of the nonlinear B-H characteristic of the magnetic material. Good agreement between the computed electro-mechanical performance and measurements has been reported. (Paper JE-05)

S. Mimounes (GE44/LRTI/CRTT, Saint-Nazaire, France) presentation dealt with a 3D coupled magnetic field/heat flow finite element formulation which has been applied to a tranformer problem. Some conclusions were presented regarding the use of a penalty term in the magnetic field formulation when high permeability magnetic materials are included in the problem domain. (Paper JE-06)

A. Konrad (University of Toronto, Toronto, Canada) explained how the integrodifferential finite element formulation can be applied to the modeling of grounding connections in multińconductor systems. The formulation has been used to study the effectiveness of eddy current shielding for the rduction of power losses in structural I- beams in arc furnace installations. (Paper JE-08)

The presentations by J. Nyenhuis (Purdue University, West Lafayette, IN) (Paper JE-09) and D. Molyneaux (Picker International, Cleveland, OH) (Paper JE-11) both dealt with subjects related to magnetic resonance imaging and measurements.

The presentation of D. Burow (Rensselaer Polytechnic Institute, Troy, NY) dealt with the calculation of forces and torques in an induction machine and the dependency of the results on the finite element mesh structure, especially the amount of distortion of the air gap elements. The conclusion was that even a small amount of element distortion may be detrimental to the accuracy of the force and torque calculations. (Paper JE-12)

NEW MAGNETICS SOCIETY FELLOWS FOR 1995

Thirteen members of the Magnetics Society were recently elected to the grade of IEEE Fellow. The new Fellows were recognized by Fritz Friedlaender, chair of the Awards Department of the Magnetics Society, at the Plenary Session of the 1995 Intermag Conference in San Antonio, Texas USA. The new Fellows evaluated by the Magnetics Society and the contributions leading to their awards are as follows.

Dr. John R. Brauer, NacNeal Schwendler Corporation, 4300 W. Brown Dear Rd., Milwaukee, WI 53223 USA, "For contributions to finite element analysis of electromagnetic devices".

Dr. Hardayal S. Gill, IBM Corporation, M/S G08/142, 5600 Cottle Road, San Jose, CA 95193 USA, "For contributions to magnetoresistive recording heads for disk file storage and retrieval".

Dr. Fred B. Hagedorn, 1000 Cordova Drive, Orlando, FL 32804 USA, "For contributions to the development of magnetic materials and devices".

Dr. Samuel R. H. Hoole, Department of Engineering, Harvey Mudd College, Claremont, CA 91711 USA, "For contributions to computational methods for design optimization of electrical devices".

Dr. Adalbert Konrad, Dept of Electrical Engineering, University of Toronto, 10 King's College Road, Toronto, Ontario, CANADA M5S 1A4, "For contributions to eddy current field computation by finite element methods".

Dr. Harry Kroger, Watson Shcool, Dept. of EE, SUNY - Binghamton, P.O. Box 6000, Binghamton, NY 13902, "For contributions to the technology of Josephson devices, and for technical leadership in electronics packaging".

Dr. Kaneo Mohri, 3911-3 Shimada Kuroishi, Tenpaku-Cho, Tenpaku-Ku, Nagoya 468, Japan, "For contributions to the research and development of sensor-magnetics".

The following new Fellows are enrolled in the Magnetics Society but were evaluated by another Society:

Dr. Alan F. Clark, Dr. George Costache, Dr. Lionel E. Davis, Dr. Kenichi Okuyama, Dr. Stephen D. Umans, and Dr. Stephen Williamson.

MAGNETIC MATERIALS SESSIONS AT MATERIALS WEEK '95

With the aim of updating scientists, engineers, and businesses on recent activities in the field of magnetic materials, the Magnetic Materials Group of ASM International’s Specialty Materials Division has organized a four session program during Materials Week '95, October 30-November 2, in Cleveland, OH.

These sessions are organized around themes important in today’s research and development environment: real world manufacturing issues; increased energy efficiency as a driver for materials development and applications; and structure-property correlations in new, advanced materials. Physicists, metallurgists, process and development engineers, and research management personnel will be interested in the developments being discussed during these sessions.

Attending this program during Materials Week presents a valuable opportunity, not only to meet with your peers in the magnetic materials community, but to meet with other ASM and TMS members attending the other 200+ technical sessions throughout the week, as well as the Materials Expo being held concurrently at the Cleveland Convention Center.

The four sessions will be Metallurgy and Physics of Magnetic Materials, Material Processing and Manufacturing, Next Generation of Magnetic Materials for Improved Energy Distribution; Panel Discussion, and ard Materials in Energy Efficient Applications. For complete programming and details on all materials Week '95 activities, call ASM's Member Services Center at 1-800-336-5152, ext. 703; FAX to 216- 338-4634; or e-mail to MemServ@po.asm-intl.org.

DIVISION IV DIRECTOR'S REPORT April, 1995

Having been in office as the IEEE Division IV Director since January this year, this is my first message to all Societies within the Division and I would like to express herewith my thanks to all of those who contributed to my successful election. As it looks, I have received a particularly high number of votes from the membership outside of the United States, namely from Regions 8, 9 and 10, which I consider at least partially as a recognition of my long year activities in the MTT-S Transnational Committee. Thanks again to all of you. I shall do my best to contribute in my new function to the globalization of the IEEE and to the promotion and support of the membership in the named regions.

Early March I participated in the TAB Meetings and Board of Directors Meetings at Calgary, Canada. These meetings and the many enjoyable and good contacts I had in parallel, gave me a first idea of the areas on which I should concentrate my IEEE activities during the next two years. In particular, I had the chance to meet most of the Presidents of the Societies within Division IV personally and got the impression that we all can make up for a very good team.

One of the first official obligations I had - and that was meanwhile finalized successfully with the help of Ken Dawson, the previous Division IV Director - was the nomination of the candidates of the new Division IV Delegate Director Elect position. Under Ken's office during the last year, the Division IV Societies had decided to opt for such a Delegate Director Elect nomination in order to create continuity for the Division IV Director office in the future. The elections will take place in November this year and we have now three excellent candidates:
Stanley H. Charap (Mag)
William G. Duff (EMC)
Orhan Nalcioglu (NPS)

All of these have been Society Presidents and all are IEEE Fellows. The one to be elected will serve in 1996 as Delegate Director Elect overlapping with my second year of office to create the desired continuity in the Division IV Director knowledge. The Elect candidate will automatically become the Division IV Director for the two years 1997/98 following my term of office. With Ken Dawson’s strong support (he acted as the Division IV Nominating Committee Chairman), the plan of our Societies regarding the Director Elect position has now been set on a regular path for the future.

A further important item of my activities at Calgary was my joining of the global RAB/TAB Transnational Committee as a member and participation in the respective meetings. This is the key committee now to elevate my previous transnational activities on the Society level to a combined effort covering all or most Societies of Division IV. In various discussions with Society Presidents I received positive reactions already to this plan and also the promise for support from the RAB/TAB Transnational Committee Chairman, Dr. Tsuneo Nakahara. The key idea is to establish a society related Transnational Committee in each of the Division IV Societies and to expand the mechanisms explored by myself in the past to the promotion of membership and chapters to all Division IV Societies. Synergies like joint chapter operations will be looked for as much as possible, keeping in mind that there is a natural overlap of technical interests between the Division IV Societies. It is also hoped that an initiative currently conducted between MTT-S and ED-S with strong participation by myself can be spread our over the Division. I shall bring this into the next RAB/TAB Committee Meeting to be held on June 22, 1995, and discuss with the colleagues then how this can be done best. Please let me have your input if you think you can contribute to this idea. I shall be happy to learn from you and plan to give a first report about the progress made in a couple of months.

Your Division IV Director
Rolf H. Jansen

IEEE Magnetics Society Newsletter is published quarterly by the Magnetics Society of The Institute of Electrical and Electronics Engineers, Inc. Headquarters of the IEEE is 345 East 47th Street, New York, NY 10017-2394, $1.00 per member per year (included in Society fee) for each member of the Magnetic Society. Printed in USA. Second-class postage paid at New York, NY and at additional mailing offices. Postmaster: Send address changes to IEEE magnetics Society Newsletter, IEEE, 445 Hoes Lane, Piscataway, NJ 08854-4150.

The objective of the IEEE Magnetics Society Newsletter is to publicize activities, conferences, workshops and other information of interest to the Society membership and technical people in the general area of applied magnetics. Copy is solicited from the Magnetics Society membership, organizers of conferences, officers of the Society and local chapters and other individuals with relevant material. The Newsletter is published in January, April, July and October. Submission deadlines are December 1, March 1, June 1, and September 1, respectively.
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IEEE MAGNETICS SOCIETY NEWSLETTER CONFERENCE CALENDAR

SEPTEMBER 11-14, 1995 Information Storage Technology Symposium (ISTS-95) Kalamata, Greece. Dr. Dennis Speliotis, Advanced Development Corp., 18 Ray Avenue, Burlington, MA 01803, USA TEL: +617-229-8992; FAX: +617-229-8997; E-mail: astc@aol.com SEPTEMBER 12-14, 1995 12th International Conference on Soft Magnetic Materials (SMM12). Krakow, Poland. Dr. Marek Gutowski, Scientific Secretary of the SMM12, Institute of Physics, Polish Academy of Sciences, A1.Lotnikow 32/46, 02-668 Warszawa, Poland, TEL: (+48 22)43-5212, FAX: (+48 22)43-0926, E-Mail: smm12@gamma1.ifpan.edu.p1. SEPTEMBER 17-20, 1995 International Symposium on Non-Liniar Electromagnetic Systems (ISEM). Cardiff, Wales, UK. ISEM 95 Secretariat, Cardiff School of Engineering, University of Wales College of Cardiff, P.O. Box 917, Newport Road, Cardiff CF2 1XH Wales, UK; TEL: +44 222 874070; FAX: +44 222 874420 OCTOBER 30- Magnetic Materials. Sessions during Materials Week. NOVEMBER 2, 1995 Cleveland, OH. Tel: ASM Member Services Center (800) 336- 5152 ext. 703; Fax: (216) 338-4634; or E-mail: MemServ@po.asm-intl.org. NOVEMBER 6-9, 1995 40th Annual Conference on Magnetism and Magnetic Materials (MMM’95). Philadelphia, Pensylvannia, USA. Diane Suiters, Courtesy Associates, 655 15th Street NW, Suite 300, Washington, DC 20005; TEL: (202) 639-5088; FAX: (202) 347-6109. APRIL 9-12, 1996 Intermag ‘96 Seattle, Washington USA Diane Suiters, Courtesy Associates, 655 15th Street NW, Suite 300, Washington, DC 20005; TEL: (202)639-5088; FAX: (202) 347-6109 APRIL 29- MAY 2, 1996 4th Magneto-Optical Recording International Symposium (MORIS’96). Noordwijkerhout, The Netherlands. J.C. Lodder, MESA-Research Institute, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands, TEL: +31 53 892750, FAX: +31 53 309547, E-Mail: lodder@el.utwente.nl.