Magnetic properties of ordered and disordered spinel-phase ferrimagnets

In spinel-phase ferrimagnets, disorder in the cation distribution between octahedral and tetrahedral sites can influence such fundamental magnetic properties as saturation magnetization, exchange coupling, and ferrimagnetic ordering temperatures. Given the sensitivity of magnetic properties to structure, it has been suggested that magnetic properties may be used as a probe of disorder in ferrimagnetic spinels. In this article, we review the fundamentals of the magnetic properties of spinel ferrites, including the interesting manifestation of noncollinear spin structures in Yafet-Kittel triangular spin configurations. This is followed by description of some experimental observations on the structure and magnetic properties of (MnxAl1-x)(3)O-4 spinels and hausmannites, which exhibit Yafet-Kittel-type ordering in their spin structures.