Mössbauer spectroscopic studies of perovskite-type oxides Ln1-xAxBO3 synthesized by sol-gel method

Synthesis of perovskite-type oxides Ln1-xAxBO3 (Ln: lanthanoid; A: alkaline earth; B: transition metal) by heating at low temperature with large ratio of alkaline earth element, especially barium, easily involves impurity of alkaline earth carbonate. We succeeded to prepare the precursor without the formation of barium carbonate even at a large content of barium. The chemical state and structure of Ln1-xAxBO3-d (Ln: La, Eu; A: Ca, Sr, Ba: B: Fe, Mn) perovskite-type oxides prepared by using those precursors have been studied by Mössbauer spectroscopy and X-ray powder diffraction. The X-ray powder patterns showed many types of crystal system depending on x.