A Way Forward? (Not necessarily “The Way Forward”). J N Chapman, University of Glasgow Synopsis Indicators of activity Magnetism in the late 20 th century A firm base within the UK? Some possible ways ahead. Hard Disc Drive Performance. The Permanent Magnet Market.
J N Chapman, University of Glasgow
MORIS NdFeB 99
Hard ferrite magnets ISEM
Soft magnetic materials TISD
Int Conf on Electrical Machines and Drives
Major sessions at:
In the 3 months leading up to this conference, Magnews listed 37 conferences!
January - June 1999
January – June 1992
Magnetic phenomena are studied:
Magnetics runs through Physics, Chemistry, Materials Science, Metallurgy, Engineering, IT.
An exciting area of condensed matter science involving exotic metals and complex oxides
Magnetism in superlattices and magnetic chains
Based on Mn oxides with the perovskite structure.
Potential for devices? - need for good room temperature performance at low fields.
Application areas are sensors (recording heads, positional for automotive application, navigational, etc.) and storage (MRAMs).
Scientific and technological challenges include:
A branch of nanoscience and technology which offers:
Scope for innovation in:
Technological driving forces include ultra-small sensors, MRAMs, quantum discs, spintronics.
Magnetic recording - hard disc and tape
As recording densities increase beyond ~70GB/sq.in, and for special applications, other technologies may be/are required:
Spintronics encompasses GMR, spin-dependent tunneling and spin-injection devices.
Coherent spin transport in semiconductors looks encouraging following 2 recent discoveries
Once the physics and materials aspects are solved, spin enhanced and enabled electronics, spin filters, spin FETs, quantum spin-electronics, coherent spin electronics are anticipated.
Control through growth conditions, processing and patterning
Increased need to measure both structural and magnetic properties as completely as possible
Importance of interfaces
Characterisation using Facilities
X-ray magnetic scattering
100T magnet - pulsed fields ~10ms duration
Rare earth - transition metal magnets (Fe and Co-based) are the subject of most research.
Starter motors, anti-lock braking systems (ABS), motor drives for wipers, injection pumps, fans and controls for windows, seats etc, loudspeakers, eddy current breaks, alternators
Loudspeakers, microphones, telephone ringers, electro-acoustic pick-ups, switches and relays
Discs drives and actuators, stepping motors, printers
DC motors for showers, washing machines, drills, citrus presses, knife sharpeners, food mixers, can openers, hair trimmers etc., low voltage DC drives for cordless appliances such as drills, hedgecutters, chainsaws, magnetic locks for cupboards and doors, loudspeakers for TV and audio, TV beam correction and focusing device, compact-disc drives, home computers, video recorders, electric clocks, analogue watches
Electronic and Instrumentation:
Sensors, contactless switches, NMR spectrometer, energy meter disc, electro-mechanical transducers, crossed field tubes, flux-transfer trip device,
DC motors for magnetic tools, robotics, magnetic separators for extracting metals and ores, magnetic bearings, servo-motor drives, lifting apparatus, brakes and clutches, meters and measuring equipment
Astro and Aerospace:
Frictionless bearings, stepping motors, couplings, instrumentation, travelling wave tubes, auto-compass
Dentures, orthopaedics, wound closures, stomach seals, repulsion collars, ferromagnetic probes, cancer cell separators, NMR body scanner
Improved performance, increased energy efficiency and the enabling of applications not previously possible is being realised with the help of:
Examples of innovation include:
There are scientific, technical and engineering opportunities in profusion - how can the UK take best advantage?
Magnetism and Magnetic Materials Initiative (1989 - 1994)
Another managed programme?
Return to responsive modes in Physics, Materials and Engineering?
If there is no EPSRC coordinator, will the UK (academic) magnetics community fragment?