Ferrimagnetic Resonance in Copper Ferrite, I. Cubic-Phase Single Crystal

抄録

The ferrimagnetic resonance in a cubic phase single crystal of CuFe₂O₄ was measured with an X-band spectrometer from 77°K to 300°K. At room temperature, K₁⁄M (the 1’st order cubic anisotropy field) and g_eff (effective g-value) are −172 Oe and 2.09, respectively. At liquid nitrogen temperature, they are −810 Oe and 2.44. The half line width is maximum (85 Oe at RT) around [100] (a hard direction of magnetization). K₁⁄M extraporated down to 0°K is about −900 Oe and K₁ (0°K) is −9.7×10⁻² cm⁻¹ per molecule. This value of K₁ (0°K) may be understood as arising from the single ion anisotropy of Fe³⁺ due to cubic crystal field splitting, and a value of a_B (Fe³⁺) (fine structure constant of Fe³⁺ on B-site in cubic crystal field) derived under some assumptions is +2.8×10⁻² cm⁻¹.