Permanent magnetism is a technology that we encounter in many phases of life: from the aids to navigation in the humble compass (China AD 1088), to the modern earphone in the Walkman. More important but less obvious uses of magnets in computers, motors, electrical generators and magnetic recording devices have spurred research into new and improved magnetic materials. Among the important qualities sought are that a permanent magnet will be strong (have a high energy product), will hold its magnetisation against opposing magnetic fields (coercivity), and will retain its properties when heated. The improvement in new materials during this century reflects research at every level, from metallurgy to theoretical physics (see Figure).

Development of the energy product of permanent magnets during the Twentieth Century.

Leadership on an international scale in the search for new magnetic materials, the understanding of why materials behave as they do, and the application of new materials in magnetic devices have been features of Professor J.M.D. Coey’s research in Trinity College for a decade and a half. Awarded the Charles Cree Medal of the Institute of Physics (London) in 1996, Mike Coey’s research has attracted financial support and industrial and academic interest from around the globe (80% of his research funds are external investment in Ireland); he has led a European wide consortium (over 70 laboratories) created to re-establish the technological competitiveness of Europe’s research on and technology competence in permanent magnetism relative to Japan and the USA. Currently he leads a European network on spin electronics.

With the support of Denis Weaire and Paul Coughlan, he set up a campus company, Magnetic Solutions, in 1994 to develop and manufacture instruments using new magnetic materials. These compact devices provide uniform, variable magnetic fields without cumbersome electrical power and water-cooling requirements. They can supersede electromagnets for many practical purposes.

The importance of new magnet technology grows as recording media and reading heads are miniaturised, and as complex processes for laying down thin films of materials are magnetically controlled. As devices using magnetism approach the nanotechnology level, the need for physicists with an understanding of the complex behaviour of magnetic materials and heterostructures will grow rapidly. An integration of magnetics with electronics (spin electronics) is a likely development, according to Coey. If we are to sustain in Ireland a modern IT industry with its own ability to master and advance new technologies, then we will need to expand and support the activities of Mike Coey’s research group, since he and his colleagues will train the solid-state engineers of future industries.