title: Charge, orbital, and magnetic ordering in YBaFe2O5 from first-principles calculations.
abstract: First principles calculations using the augmented plane wave plus local orbitals method, as implemented in the WIEN2k code, have been used to investigate the electronic and magnetic properties of YBaFe2O5, especially as regards the charge-orbital ordering. Although the total 3d charge disproportion is rather small, an orbital order parameter defined as the difference between t2g orbital occupations of Fe2+ and Fe3+ cations is large (0.73) and gives unambiguous evidence for charge and orbital ordering. Strong hybridization between O2p and Fe e g states results in the nearly complete loss of the separation between the total charges at the Fe2+ and Fe3+ atoms. Furthermore, the relationship between the orbital ordering and charge ordering is also discussed. The dxz orbital ordering is responsible for the stability of the G-type antiferromagnetic spin ordering and the charge ordering pattern.
authors.affiliation: Key Laboratory of Rare Earth Chemistry and Physics, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P.R. China.
authors.forename: Xianfeng
authors.initials: X
authors.lastname: Hao
authors.forename: Yuanhui
authors.initials: Y
authors.lastname: Xu
authors.forename: Minfeng
authors.initials: M
authors.lastname: Lv
authors.forename: Defeng
authors.initials: D
authors.lastname: Zhou
authors.forename: Zhijian
authors.initials: Z
authors.lastname: Wu
authors.forename: Jian
authors.initials: J
authors.lastname: Meng
mesh_terms: D004583:Electrons; D058085:Iron Compounds / Q000737:chemistry*; D008280:Magnetics; D011789:Quantum Theory; D015019:Yttrium / Q000737:chemistry*
chemical_list: D058085:Iron Compounds; D015019:Yttrium