Electronic states calculated by the DV-X alpha cluster method for lithium ion conductive Li2S-SiS2-Li4SiO4 oxysulfide glasses

Citation
R. Araki et al., Electronic states calculated by the DV-X alpha cluster method for lithium ion conductive Li2S-SiS2-Li4SiO4 oxysulfide glasses, J NON-CRYST, 288(1-3), 2001, pp. 1-7
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF NON-CRYSTALLINE SOLIDS
ISSN journal
0022-3093 → ACNP
Volume
288
Issue
1-3
Year of publication
2001
Pages
1 - 7
Database
ISI
SICI code
0022-3093(200108)288:1-3<1:ESCBTD>2.0.ZU;2-Z
Abstract
The electronic states of the Li2S-SiS2-Li4SiO4 oxysulfide glasses were inve stigated by using the DV-X alpha cluster method as a non-empirical molecula r orbital calculation. The calculation was carried out for the dimer-framed Li6Si2OmSn (m + n = 7) cluster models expected to be present in the oxysul fide glasses. The bond states around lithium ions changed from covalent to ionic with an increase in the number of non-bridging oxygens. The increase of covalency of the Si-S and Si-O bonds in the frame structure brought abou t the increase of covalency between the frame and lithium ions. The bond st ates around lithium ions of the cluster with one bridging oxygen were simil ar to those of the cluster in the pure sulfide glasses. This similarity see ms to be one of the reasons for high ionic conductivities, over 10(4) S cm( -1), in the oxysulfide glasses with small amounts of lithium ortho-oxosalts . (C) 2001 Elsevier Science B.V, All rights reserved.