A temperature-dependent Mössbauer study of CeSn3 and CeSn3.1 single crystals

The 119Sn Mössbauer spectra have been measured for the intermediate valent CeSn3 (stoichiometric) and CeSn3.1 (slightly non-stoichiometric) high-quality single crystals in the temperature range from 300 to 30 K with an aim to look into the local surrounding of the Sn site and its valence state in these crystals. The spectra clearly indicate a para-magnetic ground state throughout the temperature range. Two different doublets with a quadrupole interaction that we associate with two different paramagnetic S1 and S2 sites, result from our first attempt to fit the experimental spectra, the ratio between these sites S1/S2 being around 3/1. The magnitudes of isomer shift reveal a 2+ valence state for the Sn, that does not show any change for either the S1 or the S2 sites, in the whole investigated temperature range. The different values of quadrupole splitting ΔEQ for S1 and S2 again confirm that the Sn atoms have different atomic coordinations.