Study of magnetic relaxation in the perovskite SrLaFeSnO6 by Mössbauer spectroscopy

Abstract

The temperature dependence of the ⁵⁷Fe and ¹¹⁹Sn Mössbauer spectra of SrLaFeSnO₆ has revealed the existence of unusual magnetic relaxation behaviour. The transferred hyperfine interactions in the Sn resonance at 4.2 K establish that the Fe and Sn cations are disordered. An explanation is developed in terms of the formation of magnetic clusters below ca. 220 K which increase in size with decreasing temperature until a long-range ordered G-type antiferromagnetic structure is achieved below ca. 38 K. This behaviour is intermediate between a true antiferromagnet and a spin-glass. A reinterpretation of the related SrFe_{1 –x}Sn_xO_{3 –y} system is given which suggests that compositions in the region of Sr₂FeSnO_5.71 may also exhibit spin-glass behaviour.