Mössbauer Study of Supertransferred Hyperfine Field of ¹¹⁹Sn (Sn⁴⁺) in Ca_1−xSr_xMnO₃

Abstract

Ca_1−xSr_xMn_0.99Sn_0.01O₃(0≤x≤1) with (nearly) cubic perovskite structures were prepared and the magnetic hyperfine fields of ¹¹⁹Sn(Sn⁴⁺) were measured by the Mössbauer effect. The hyperfine fields arise from unpaired s electron spin densities transferred from Mn⁴⁺ ions (super-transferred hyperfine interaction). The hyperfine field for a tin ion was found to depend linearly upon the numbers of Ca²⁺ and Sr²⁺ ions in the neighboring divalent cation sites, with proportional coefficients having opposite signs. To explain experimental results two kinds of spin transfer processes contributing to the hyperfine field oppositely to each other have been considered, and spin transfer via a divalent cation is emphasized particularly. The hyperfine field at 0 K for Sn⁴⁺ in CaMnO₃ is −75 kOe, while +20 kOe for Sn⁴⁺ in SrMnO₃.