Anisotropy of gadolinium iron garnet

Abstract

The ''one-ion'' theory of origin of anisotropy has been tested by comparing the calculated value of the gadolinium contribution to the anisotropy of GdIG at 0°K with experimental measurements. Crystal field, dipolar, and dipole - crystal field effects are included in the calculation. The median of the values obtained using the crystal field parameters for Gd3+ in four diamagnetic garnets agrees within 3 with the result of torque measurements on a pure GdIG crystal. The experimental value, -21.9×104 ergscc, is approximately 10 lower than previous values for the anisotropy of GdIG. The good agreement between the calculated and experimental anisotropies provides quantitative confirmation of the theory used in the calculations. © 1963 The American Institute of Physics.