Cation Distribution in a Series of Mixed Ferrites MgxMn1.1−xSn0.1Fe1.8O4 by Means of Powder X-Ray Diffraction and 57Fe, 119Sn Mössbauer Spectroscopy

The cation distribution in a series of MgxMn1.1−xSn0.1Fe1.8O4 spinel ferrites has been studied by means of X-ray powder diffraction and 57Fe, 119Sn Mossbauer spectroscopy. All of these ferrites showed broad 119Sn Mossbauer spectra due to the hyperfine magnetic field from the ferrimagnetically ordered cations at the A and B sites. With increasing x the distribution of the hyperfine field at the Sn atom became broader and the hyperfine field decreased abruptly above x=0.825. This observation indicates that diamagnetic Mg2+ ions are excluded from the A site below x=0.55, but occupy the A site as well as the B site only above x=0.825. This result is consistent with the Rietveld analyses of the X-ray powder diffraction data. The 119Sn Mossbauer spectroscopy is shown to be a useful technique for studying the cation distribution of ternary spinels in which the site preference of cations can not be empirically predicted.