Electronic structure of the perovskite oxides La1−xSrxMnO3

• DOI: 10.1016/j.physleta.2005.10.095
• Publication Date: 2005-11-03T13:52:41Z
• Authors: Tao Geng; Ning Zhang
• Keywords: Tetragonal crystal system; Jahn–Teller effect; Distortion (music); Crystal (programming language)

Abstract The electronic structures of perovskite oxides La1−xSrxMnO3 are studied with local spin-density approximation (LSDA). Results show that the lowest energy is obtained when the Mn O bond length is 1.95 A with ideal cubic crystal structure. This value of Mn O bond length is consistent with the experimental data. Considering a proper tetragonal distortion of the crystal, the total energy of system becomes lower. A half-metal state can be got both for the undistorted structure (Mn O bond lengths are 1.95–2.10 A) and the distorted structure. It is suggested that the effect of Jahn–Teller distortion is not the main reason of formation of half-metal state. However, the electronic properties are very sensitive to the c / a ratio. Along with the increase of c / a ratio, system transforms from metal to half metal and further the insulator.