Effect of pressure on resistivity and Mouml;ssbauer spectra of the mixed valence compound Sn2S3

摘要

A continuous decrease of the resistivity by five orders of magnitude has been observed on Sn2S3at room temperature under pressures up to 120 kbar. PbSnS3shows only a decrease by three orders of magnitude. SnGeS3and PbGeS3remain insulators in the same pressure range. Mouml;ssbauer measurements on119Sn in Sn2S3at room temperature and pressures up to 55 kbar indicate that Sn2S3remains a type I mixed valence compound in this pressure range. The two crystallographic positions of Sn exhibit significantly different Debye temperatures, THgr;D(SnII) =207 K, THgr;D(SnIV) =429 K. Moreover, distinct119Sn pressure shifts part;dgr; (SnII)/part;Pquest;+2.1 mm/sec kbar and part;dgr; (SnIV)/part;pquest;+1.2 mm/sec kbar are observed.