Magnetocrystalline Anisotropy of Rare-Earth Iron Garnets

Abstract

This paper will review recent anisotropy data, deduced from static and resonance measurements, on the rare‐earth iron garnets of formula 5Fe₂O₃ 3M₂O₃, where M is Y, Gd, Yb, Er, Sm, Tb, Dy, and Ho, respectively. Both the high temperature behavior (up to 300°K) which can be expressed in terms of the anisotropy constants K₁ and K₂ and the anomalous anisotropy properties which occur at liquid helium temperatures are discussed. The results are interpreted in terms of the single ion model which considers the anisotropy resulting from the effect of the combined crystal and exchange fields of the garnet on the energy levels of the individual magnetic ions, and the extent to which this model can describe the anisotropy of rare‐earth iron garnets will be briefly discussed.