X-ray spectroscopy investigation of the electronic structure of SnSx and Li0.57SnS2 compounds

摘要

Photoemission spectroscopy and X-ray emission spectroscopy have been used to investigate the role of the chemical environment on the electronic structure of SnS, SnS2, Sn2S3 and Li0.57SnS2 compounds. For this purpose, we have studied the Sn 3d(5/2) and S 2P(1/2,3/2) inner levels and the valence band by photoemission spectroscopy and the S 3p electronic distributions by X-ray emission spectroscopy. We have established fingerprints of the Sn-II and Sn-IV valencies in the compounds SnS and SnS2 and have shown that these are observed in Sn2S3 where it is known that both II and IV valencies are present. By comparing the data for Li0.57SnS2 with those for the other compounds, we have demonstrated that the Sn-II and Sn-IV signatures are also found in this compound. We have thus ascertained experimentally that Sn is partially reduced in SnS2 upon Li intercalation. In addition, the data have been found to be in excellent agreement with recent densities of electronic states calculations performed in the framework of the density functional theory for the same compounds. [References: 11]