Theory of the Magnetic and Optical Properties ofCr2O3

Abstract

${\mathrm{Cr}}_2$ ${\mathrm{O}}_3$ is discussed from the point of view of pairs of Cr ions with strong exchange coupling between members of the pair and subjected to a relatively weak molecular field. This is done using the Oguchi method. The anomalous behavior of the parallel susceptibility above $T_N$ and low-temperature spin-saturation value are explained. If the spin system is assumed to be canted, it is possible to explain the nonzero value of ${\chi }_{\parallel }$ at 0°K and the resultant optical properties are found to be in good agreement with experiment.