Spin/orbital coupling and charge ordering in LaMnO3/SrMnO3 superlattice

Coupled spin, orbital and charge ordering in half-doped perovskite La1/2Sr1/2MnO3 (LSMO) superlattice are quantitatively investigated in realspace using the generalized gradient approximation (GGA) plus on-site Coulomb repulsion U (GGA+U) method. It is found that the high spin Mn3+ site exhibits an elongation of MnO6 octahedral for the Jahn-Teller distortion, with estimated distortion energy about 0.1 eV. The occupied e(g) states of Mn3+ cations are predominantly of dz(2) character, which contribute mainly to the orbital ordering in LSMO. Mn3+ and Mn4+ ions show electronic disproportionation and lead to an e(g) charge ordering distribution. As the thickness of one period of LSMO superlattice increases, the spin magnetic moments increase and the charge order effect reduces. (C) 2012 Elsevier BY. All rights reserved.