Magnetic Susceptibility of Potassium Hexachlororhenate (IV) and Potassium Hexabromorhenate (IV) from 5° to 300°K

Abstract

The Curie points of K2ReCl6 and K2ReBr6 obtained from magnetic susceptibility measurements are 12.4±0.5° and 15.3±0.5°K, respectively, which confirm that cooperative-type transitions observed in the heat capacities of these compounds with maxima at 11.9±0.1° and 15.2±0.1°K, respectively, represent transitions to the antiferromagnetic state. Evidence is presented that the ratios of the next nearest-neighbor to nearest-neighbor superexchange interactions in the two compounds are approximately equal. An estimate of the spin-orbit coupling constants in the crystals is given and compared with other estimates.