Influence of Fe in the local Structure of Perovskite Compound La_2/3Ca_l/3Fe_l-xMn_xO₃

The ceramic samples with nominal composition of La_2/3Ca_l/3Mn_l-xFe_xO₃ (0.01 ≤ x ≤ 0.20) were prepared by solid state reaction method. The effect of Fe doping on the Mn site was measured by the positron annihilation technique and Mössbauer spectroscopy. Upon doping, no appreciable structure change and electronic structure change in Mn-O plane were observed in the series of compounds. The Mössbauer parameters show that the iron probe has stable 3+ valance with the high spin state in all samples. Moreover, by examining the shape of the spectra, the tendency can be found that the isomer shift and quadruploe splitting increase with the increasing Fe⁺³ content. This phenomenon shows the local lattice distortion and the localization of d-electrons with the increasing Fe-doping content.