LCAO analysis of the electron band structure and Fermi surface of cubic superconducting perovskites

✍ Scribed by Todor M. Mishonov; Ivan N. Gentchev; Radostina K. Koleva; Evgeni S. Penev

• Publisher: Elsevier Science
• Year: 1997
• Tongue: English
• Weight: 245 KB
• Volume: 21
• Category: Article
• ISSN: 0749-6036
• DOI: 10.1006/spmi.1996.0421

✦ Synopsis

Simple analytical expressions for the electron band dispersion (p) are obtained within the framework of a tight-binding model. Formulae for the Fermi surface p z = p z ( p x , p y ; E F ) are derived as well. O p σ states of the perovskite anion and s state of small cation Bi6s are taken into account. The hopping amplitude between next-nearest neighbours is considered as a small parameter of the theory and an effective oxygen Hamiltonian is derived. Band dispersions and density of states are graphically presented. Isoenergy surfaces of cubic bismuthates for the particular case E F /w cd = 0.38 (w cd is the band width) are shown and discussed as well. The adopted model can be used as a realistic one-electron part of the tight-binding models of superconducting perovskites.