X-Ray Diffraction and Magnetic Measurements of the Fe-Cr Spinels

X-ray diffraction intensity measurements and magnetic moment measurements were made on the spinel system $\mathrm{Fe}{\mathrm{Fe}}_{2-x}{\mathrm{Cr}}_x{\mathrm{O}}_4$, $0\le x\le 2$, for the purpose of finding structural details in this system which were unknown. The x-ray measurements covered the entire composition range, and the magnetic measurements covered the range from $x=0\mathrm{}$ to $x=1.2\mathrm{}$. From the x-ray measurements the oxygen parameter of each sample was deduced. These parameters indicated inverse spinels for low values of $x$, partially inverse spinels for intermediate values of $x$, and normal spinels for $x=1.3\mathrm{}$ to $x=2\mathrm{}$.