Electronic structure calculations for two-dimensional transition metal oxides

✍ Scribed by Kimichika Fukushima; Hirohiko Adachi

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 598 KB
• Volume: 207
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90430-x

✦ Synopsis

Electronic states of oxides including 3d, 4d and 5d transition metals with metal ion d t configuration were calculated using the spin-polarized DV-Xa method. Artificial model clusters adopted were MO6 octahedra, MO5 pyramids and square planar MO4 (M=transition metal). For the undistorted octahedron, d orbitals of the metal ion split into partially occupied levels t2s and unoccupied levels e,. The degenerate orbitals t2t, whose components are dx~, d~ and d~, do not have a two-dimensional character. For the octahedron whose M-O bonds in the xy(ab)-plane are elongated, metal d~v and oxygen Px form two-dimensional halffilled states. In this case, the metal oxide probably becomes an insulator, and the p~ contribution to the half-filled states increases as the atomic number becomes larger. Concerning the square planar, metal dz2, oxygen po and metal s form the two-dimensional half-filled states. The energy separation between d and p orbitals is smaller compared to the octahedron.