Cavendish Laboratory, University of Cambridge.
Most thin magnetic films have their magnetization lying in the plane of the film because of shape anisotropy. In recent years there has been a resurgence of interest in thin magnetic films which exhibit a magnetization easy axis along the surface normal due to so-called Perpendicular Magnetic Anisotropy (PMA). PMA has its origins in the symmetry breaking which occurs at surfaces and interfaces and can be strong enough to dominate the magnetic properties of some material systems. In this talk I explain the physics of such materials and show how the magnetic properties associated with PMA are often very well suited to applications. I show three different examples of real and potential applications of PMA materials: ultralow power STT-MRAM memory devices for green computing, 3-dimensional magnetic logic structures and a novel cancer therapy.
Ivan K. Schuller
Physics Department and Center for Advanced Nanoscience. University of California-San Diego
Hybrid heterostructured materials allow the development of new material properties by creative uses of proximity effects. When two dissimilar materials are in close physical proximity the properties of each one may be radically modified and occasionally a completely new material emerges. In the area of magnetism, controlling the magnetic properties of ferromagnetic thin films without magnetic fields is an on-going challenge with multiple technological implications for low-energy memory and logic devices. All these are based on basic discoveries, which provide the scientific foundation for important applications. Of course like with all basic research discoveries it is difficult to predict where and when these will make it into applications.
IFW Dresden, Institute of Metallic Materials TU Dresden, Institute of Materials Science evivo GmbH, Dresden Int. Lab. of High Magnetic Fields and Low Temperatures, Wroclaw
New means of urban transportation and logistics will become realistic with superconducting magnetic bearings using bulk high temperature superconductors. The advantage of super¬con-ducting magnetic levitation is that it works passively stable without any electronic control but with attracting and repelling forces to suspend a vehicle pendant or standing upright from zero to high speed - perfect conditions for the idea of rail-bound individual transport with cabins for 4 - 5 passengers requested call by call. They will levitate noiseless over the track made of RE permanent magnets saving energy and travel time. A big step forward to this vision has been made in Dresden. The world largest research and test facility for transport systems using HTS bulk material in the levitation and guidance system in combination with a permanent magnet track was put into operation. A vehicle for 2 passengers, equipped with linear drive propulsion, non-contact energy supply, second braking system and various test and measurement systems is running on an 80 m long oval driveway. In the presentation the principle of superconducting levitation by flux pinning in high temperature supercon¬ductors will be described. Based on this an overview of the SupraTrans II research facility and future directions of super¬conductivity-based magnetic levitation and bearing for automation technology, transportation and medical treatment under enhanced gravity will be given.
ECE Department, University of Minnesota
Magnetic nanowires can have many names: bits, sensors, heads, artificial cilia, sensors, and nano-bots. These applications require nanometer control of dimensions, while incorporating various metals and alloys. To realize this control, 7- to 200-nm diameter nanowires are synthesized within insulating matrices by direct electrochemistry. Our nanowires can easily have lengths 10,000x their diameters, and they are often layered with magnetic and non-magnetic metals as required by each application. This talk will reveal synthesis secrets for nm-control of layer thicknesses, even for difficult alloys, which has enabled studies of magnetization reversal, magneto-elasticity, giant magnetoresistance, and spin transfer torque switching. These nanowires will mitigate the ITRS Roadmap’s “Size Effect” Grand Challenge which identifies the high resistivities in small interconnects as a barrier to continued progress along Moore’s Law (or better). High magnetoresistance is also possible in other multilayered nanowires that exhibit excellent properties for mulit-level nonvolatile random access memory. If the insulating growth matrix is etched away, the nanowires resemble a magnetic bed of nano-seaweed which enables microfluidic flow sensors and vibration sensors. Finally, we have incubated various nanowires with several healthy and cancerous cell lines, and find that they are readily internalized. Careful magnetic design of these “nano-bots” enables external steering, nano-barcode identification, and several modes of therapy.