Intrinsic and Extrinsic Properties of Advanced Magnetic Materials

Abstract

Magnetic materials have inspired human imagination for millennia, and for many centuries they have stimulated progress in science and technology. For a long time, focus has been on naturally occurring magnetic materials, such as iron and magnetite (see Fig. 1.1). In the last few decades, there has been a revolution in the development of magnetic materials. On one hand, atomic-scale quantum-mechanical and relativistic effects have been exploited to create high-performance magnetic materials, such as the alloys SmCo₅ and Nd₂Fe₁₄B, which are used to produce permanent magnets. On the other hand, geometrically well-defined nanostructures such as multilayers, particle arrays and bulk composites, are now actively explored and used to fabricate magnetic materials for a wide range of applications (Coehoorn et al., 1988; Baibich et al., 1988; Skomski and Coey, 1993; McCurrie, 1994; Himpsel et al., 1998; Comstock, 1999; Wood, 2000; Weller et al., 2000; Ziese and Thornton, 2001; Sellmyer et al., 2002).