Rietveld Refinements of K2NiF4-Type Phases Ln(0.5)Sr(1.5)Mn(0.5)Fe(0.5)O(4) (Ln = La, Nd, Gd, and Dy)

A study was conducted to to investigate structural characterization of the Ln0.5Sr1.5Mn0.5Fe0.5O4 phases by Rietveld analysis using GSAS program. The bond angles and bond distances were determined on the basis of structural parameters derived from structural refinements. The structure refinements for the phases were carried out using the tetragonal unit cell in the space group I4/mmm. The background Rietveld refinement was fitted with a shifted Chebyschev polynomial function, and pseudo-Voight function was employed to model the peak shapes in all cases. The occupation factors for the metals were fixed by considering sample stoichiometry, assuming that the Ln/Sr cations were randomly distributed while those of oxygen atoms were refined.