Anisotropy and Spin-Orbit Coupling

This lecture covers the concepts of anisotropy in magnetic materials, including the anisotropic magnetic hysteresis of iron, comparison of iron, nickel, and cobalt, and magnetocrystalline anisotropy. It also delves into the effects of spin-orbit coupling on magnetic anisotropy, explaining the change of orbital functions when rotating magnetization. The presentation discusses the work done in magnetization curves, potential energy per unit volume for a magnet, and the energy representing hysteresis loss. The instructor emphasizes the relationship between the magnetization process of a material and its crystallographic structure, highlighting the symmetry axes and planes in a cubic crystal. Additionally, spin-orbit coupling is explored through the magnetic field in the electron frame, illustrating the interaction energy and the effective magnetic field at the electron.