Determination of Cation Distribution in Mn–Zn–Fe Ferrite by X-Ray Anomalous Scattering

Abstract

Site preferency of cations in Mn–Zn–Fe ferrite, Mn 0.54 Zn 0.35 Fe 2.11 O 4 , has been investigated using spherical single crystals with synchrotron X-rays. The anomalous scattering effect was applied to diffraction experiments in a four-circle diffractometry at wavelengths of 1.7535 and 1.2934 Å which are 0.01 Å longer than Fe K - and Zn K -absorption edges, respectively. The two-wavelengths anomalous dispersion (TWAD) method allowed us to determine the cation distributions accurately with a large difference in atomic scattering factors. The result shows that all Mn and Zn ions fully occupy the tetrahedral A sites within the experimental errors, suggesting that Mn–Zn–Fe ferrite has the crystal structure of a typical normal spinel. The chemical formula is [Mn 0.54 Zn 0.34 Fe 0.12 ] A [Zn 0.01 Fe 1.99 ] B O 4 . The cell dimension and u parameter are a =8.4727±0.0006 Å and u =0.2609±0.0002, respectively.