High-temperature Mössbauer studies on 119Sn-enriched caesium tin(II) chlorides and bromides

Abstract

Variable-temperature Mössbauer studies have been carried out on ¹¹⁹Sn-enriched samples of CsSnBr₃, Cs₄SnBr₆, CsSnCl₃ and Cs₄SnCl₆. Significant changes found in the chemical isomer shift and quadrupole splitting or linewidth parameters with temperature are compared with changes in electrical conductivity. In each case the shift decreases with increasing temperature over a range of temperatures to a value which coincides with a minimum in the linewidth and with maximum conductivity. The changes observed are consistent with the direct population of solid-state bands by the non-bonding electrons on the tin(II) and with the changes expected from orbital-matching arguments.