Charge Density Wave Transitions Induced in Nb3Se4and Nb3S4by Indium Intercalation

✍ Scribed by F.W. Boswell; J.C. Bennett; A. Prodan

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 241 KB
• Volume: 144
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8207

✦ Synopsis

The family of crystals Nb 3 X 4 (X ‫؍‬ Te, Se, S) are isostructural, quasi one-dimensional tunnel structures. The telluride exhibits a charge density wave below room temperature, but no such transition occurs in the selenide or sul5de. A variety of foreign atoms can be intercalated into the tunnels of these structures and it is known that thallium intercalation in Nb 3 Te 4 causes dramatic changes in the charge density wave characteristics, due to changes in the Fermi surface and density of states resulting from the electrons being transferred to the host crystal from the intercalated atoms. In this paper it is shown that indium intercalation in Nb 3 Se 4 and Nb 3 S 4 gives rise to superlattice re6ections in electron di4raction patterns, which are interpreted as being due to charge density waves. The unusual variations of the charge density wave vectors with intercalate concentration are discussed and a model to account for them is proposed.