Magnetic Properties of the Manganese Chromite-Aluminates

The mixed-crystal spinel series $\mathrm{Mn}{\mathrm{Cr}}_{2-t}{\mathrm{Al}}_t{\mathrm{O}}_4$ has been synthesized and found to form a single cubic phase with a cell edge that is a linear function of the aluminum content. An x-ray study indicates that the series is an almost-normal spinel series with the $A$ sites occupied by divalent manganese ions and about 5% of the trivalent aluminum ions.