The metal-insulator transition in disordered tungsten bronzes. Results of an Anderson-Mott-Hubbard model

Conference item

To understand the electronic properties - in particular the metal -insulator transition (MIT) - of cubic tungsten bronzes NaxWO3 and NaxTayW1-yO3, a microscopic model incorporating electron interactions and correlated disorder is presented and treated at the mean-field level of unrestricted Hartree-Fock. The conduction band is found to exhibit a pseudogap at the Fermi level for sufficiently large interaction strengths, in agreement with experiment. The pseudogap has a profound effect on localization properties of Fermi-level states and the position of the MIT. The lower band-edge states are found to be essentially two-dimensional, with a progressive crossover to three-dimensional character with increasing energy. An exception to this behaviour occurs in the pseudogap, where the states are virtually two-dimensional.

Authors: Ducker, H; Koslowski, T; vonNiessen, W; Tusch, M; Logan, D

• Publication status: Published
• Host title: JOURNAL OF NON-CRYSTALLINE SOLIDS
• Volume: 205
• Issue: 1
• Pages: 32-42
• Publication date: 1996-10-01
• DOI: 10.1016/S0022-3093(96)00426-7
• ISSN: 0022-3093