Cation Distributions in Ferrospinels. Magnesium-Manganese Ferrites

The saturation magnetization as a function of quench temperature is measured for the ferrite system ${\mathrm{Mg}}_y{\mathrm{Mn}}_{1-y}{\mathrm{Fe}}_2{\mathrm{O}}_4$. From these data the ionic distribution of Mg ions is evaluated and compared to the theoretical thermodynamic analysis developed in the preceding paper. The interesting quantity $\frac{\partial u_1}{\partial \eta }$, where $u_1$ is the nonthermal energy and $\eta$ is the fraction of Mg ions on $A$ sites, can be evaluated from the data only if the variation of the Debye temperature with $\eta$ can be neglected. If this assumption is made, then it is found that $\frac{\partial u_1}{\partial \eta }$ is linearly dependent on $\eta$. The lattice constant has also been determined as a function of quench temperature.