Chapter 3 Interstitially modified intermetallics of rare earth and 3D elements

Abstract

Publisher Summary This chapter describes the interstitially modified intermetallics of rare earth and 3D elements. The discovery that metastable intermetallic compounds can be produced by a process of gas-phase interstitial modification has significantly widened the range of rare earth intermetallics with intrinsic magnetic properties suitable for use as permanent magnets. To have a sufficiently high magnetic hardness and a reasonable temperature stability, high magnetization and high Curie temperature are essential for new materials suitable for permanent magnet applications. The intrinsic magnetic properties at room temperature for some well known permanent magnet materials are also discussed in the chapter. Permanent magnets with different levels of ( BH )max have their own market according to different requirement in various kinds of applications. The main contribution to the magnetic anisotropy in permanent magnet materials is the crystal-field induced single-ion anisotropy on the magnetic rare earth-atoms. The 4f moment of the rare-earth atoms will prefer a certain magnetization direction that is determined by the properties of the rare-earth atoms and the crystal electric field at the particular crystallographic sites.