ABSTRACT
This chapter discusses the physical properties of amorphous rare earth-transition metal and rare earth-noble metal alloys containing non S-state rare earth ions, in which the coupling to the immediate environment gives rise to a local magnetic anisotropy, i.e., a random magnetic anistropy. It aims to study the physical properties of amorphous non-S-state rare earth alloys in terms of the model Hamiltonian 1.7 and where possible to compare with the experimental results. The magnetic properties of the hard amorphous magnetic alloys should depend on the nature of strong electrostatic fields acting on the rare-earth atoms. In the crystalline materials, such crystal fields indeed are responsible for the huge magnetocrystalline anisotropy and magnetostriction. Ideally, an amorphous material is isotropic on the macroscopic scale, so that there is no macroscopic magnet anisotropy. The random local anisotropy may have important effects on the ground state and the coercivity of an amorphous magnetic material.
