Magnetic exchange interactions in perovskite solid solutions. Part 6. Iron-57 and tin-119 Mössbauer spectra of SrFe1 –xSnxO3 –y(0 ⩽x⩽ 0.7)

Abstract

The oxygen-deficient perovskite phase SrFe_{1 –x}Sn_xO_{3 –y}(0 ⩽x⩽ 0.7) has been studied using ⁵⁷Fe and ¹¹⁹Sn Mössbauer spectroscopy and X-ray powder diffraction. The oxygen content of each sample depends on its thermal history, and magnetic ordering occurs at low temperatures. The aggregation of oxygen vacancies to produce layers of tetrahedrally co-ordinated Fe³⁺ cations which occurs for x= 0 appears to be suppressed by the tin substitution. The supertransferred hyperfine field interaction at tin reveals a continuous distribution of fields, and the spectroscopic data are consistent with a delocalised-electron behaviour in which the more usual near-neighbour interactions are obscured by longer-range effects.