MAGNETIC AND CRYSTALLOGRAPHIC PROPERTIES OF SYSTEM MNCR2S4-MNINCRS4

The system MnInxCr2-xS4 was prepared and its crystallographic and magnetic properties studied in order to better understand the anomalous antiferromagnetism observed for MnInCrS4. X-ray studies showed that the compounds throughout the series formed spinel structures having unit cell parameters which increased as a linear function of composition from x=0 to x=1. The A sites are always occupied solely by the Mn2+ ions. Therefore, all the In3+ ions are substituted for Cr3+ ions on the B sites. The materials in the compositional range 0≤x<0.4 were found to be ferrimagnetic. For 0.4≤x≤1.0, the samples were antiferromagnetic. The magnetization, Curie and Néel temperatures, and the high-temperature susceptibilities were measured. The Curie constant and the Curie-Weiss θ were determined for each composition. As observed previously for MnCr2S4 and MnCr2O 4, the Curie constants of this system were found to be lower than those which are theoretically expected. A discussion of the possible exchange interactions responsible for the antiferromagnetism of MnInCrS4 is presented. © 1968 The American Institute of Physics.