Triangular Moment Arrangements in Manganese-Iron Spinels

Abstract

The anomalously low magnetic moments for MnxFe 3-xO4 spinels with 1<x≤3 are qualitatively explained by a Yafet-Kittel triangular moment arrangement. Values of β, n, and α are calculated from measurements of magnetic moment, high field susceptibility, and Curie temperature. The measurements on Mn3O 4 yield a moment of 1.73 Bohr magnetons and a susceptibility of 3.5×10-4 gauss/oersted. An extrapolated anisotropy field of 150 kilo-oersted is found. Transitions from the triangular state to a Néel-type arrangement are found to occur for x = 1.25, x = 1.55, and x = 1.80. For Mn3O4, αβ values suggest that the vanishing of the spontaneous magnetization at 42°K represents a transition to a paramagnetic-antiferromagnetic state. © 1961 The American Institute of Physics.