Anisotropy Fields in Hexagonal Ferrimagnetic Oxides by Ferrimagnetic Resonance

Abstract

Room-temperature microwave ferrimagnetic resonance measurements of the large uniaxial magnetocrystalline anisotropy fields (Han) of two compositional series of hexagonal ferrimagnetic oxides are reported. Han was found to increase rapidly in the Al-substitution series (SrO·xAl2O3·(6−x)Fe2O3) from 19.3 to 53.4 kOe as x was increased from 0 to 1.7. In the TiCo series (BaO·x[TiCoO3]·(6−x)Fe2O3), Han was found to decrease from 17.5 to 6.6 kOe as x was increased from 0 to 0.78. Experimental plots are given for the variation of Han with x. The linewidths of these oriented polycrystalline compounds were all about 2 kOe. The g value was consistently found to be about 1.9. Variation with x of the respective saturation magnetizations, anisotropy constants, and anisotropy fields are discussed; relations are presented.