Crystallographic Study of Chromium Spinels

Several chromium spinels have been prepared and regular x‐ray diffraction intensities were measured on the powders. A Fortran program was developed in order to process the data. It appeared that the results, so obtained, were comparable to those from neutron diffraction techniques. A plot of the U parameter versus a0 for the thiochromites shows that metallic CuCr2S4 is exceptional. For its value of U, it has a much lower a0 than would be expected from a comparison of Mn, Fe, Co, and Zn thiochromites.