An improved X-ray structural analysis for determining cation distribution in ZnFe₂O₄ and ZnFe₂O₄- Fe₃O₄ solid solutions

Abstract

The distribution of zinc cation between crystallographically nonequivalent positions in ZnFe₂0₄ has been determined by anomalous X-ray scattering near the Zn K absorption edge. Measured intensity ratio with two energies close to the edge can be quantitatively explained only by assigning all zinc cations to the tetrahedral position in the approximately cubic close packed array of oxygen ions. A similar conclusion has also been reached for Zn_xFe_3-x0₄ solid solutions with x = 0.73, 0.54 and 0.35 employing the improved X-ray method. This is consistent with the EXAFS results which indicate an almost unchanged environmental structure around zinc cation in these solid solutions.