LOCAL ENVIRONMENT OF TIN IN LAYERED SNSE2XS2(1-X) COMPOUNDS BY SN-119MOSSBAUER-SPECTROSCOPY

The local environment of tin atoms in SnSe2xS2(1-x) (x=0-1) solid solu tions has been studied by Sn-119 Mossbauer spectroscopy. A linear incr ease of the Mossbauer isomer shift delta as a function of x is observe d. First, we show that this result is in good agreement with a tight-b inding evaluation of the Mossbauer isomer shift which takes into accou nt the experimental values of the lattice parameters. Then, we propose a molecular calculation which provides a rather simple explanation of the linear relationship of delta and x based on the description of th e local Sn environment.