TEMPERATURE AND FIELD DEPENDENT MÖSSBAUER STUDY OF CeSn3andCeSn3.1 CRYSTALS

Mossbauer spectroscopic measurements have been carried out for CeSn3 and CeSn3.1 single crystals in the temperature range 1.5 K to 300 K under applied magnetic field, with an aim to look into the local surroundings of the Sn site and the possibility of magnetization at low temperatures. The spectra indicate a paramagnetic ground state throughout the temperature range with two different doublets associated with two sites S1 and S2. This indicates two crystallographic sites of Sn with the presence of a distortion in the cubic crystal. However, the contribution of S2 site is very small (only 3% for the CeSn3 but slightly higher, i.e., 4.3% for the CeSn3.1) at room temperature. Upon cooling (below 4 K), the S2 contribution disappears for the stoichiometric sample (CeSn3) but continues to stay for the slightly nonstoichiometric compound (CeSn3.1). The isomer shift reveals a Sn2+ valence state throughout. A weak hyperfine field has been observed only at low temperatures (4.2 and 1.5 K spectra) for both the comp...