Superexchange interactions in Cu0.5Fe0.5Rh0.5Cr1.5S4

Abstract Cu 0.5 Fe 0.5 Rh 0.5 Cr 1.5 S 4 has been studied by Mossbauer spectroscopy, X-ray diffraction, and magnetization measurement. The crystal is found to have a cubic spinel structure with the lattice constant a 0 = 9.859 ± 0.005 A . The iron ions are in ferric states and occupy the tetrahedral sites. The temperature dependence of both the magnetic hyperfine field and magnetization is explained by the Neel theory of ferromagnetism using three exchange integrals: J Fe-Cr k B = −13.76 K , J Fe-Fe k B = −8.08 K , and J Cr-Cr k B = 8.53 K . Neel temperature and Debye temperature are found to be 288 ± 2 K and 533 ± 5 K, respectively.