title: Effects of layered structural features on charge/orbital ordering in (La, Sr)(n+1)Mn(n)O(3n+1) (n = 1 and 2).
abstract: The charge/orbital ordering (COO) of the layered mixed-valence manganites (La,Sr)(n+1)Mn(n)O(3n+1) (n = 1 and 2) is examined by first-principles calculations and discussed in comparison with the La(0.5)Ca(0.5)MnO(3) perovskite phase ([Formula: see text]). The results demonstrated that the layered structural features could yield not only visibly weak coupling between Mn-O layers but also various features in the orbital ordering associated with different types of local structural distortions. In both La(0.5)Sr(1.5)MnO(4) (n = 1) and LaSr(2)Mn(2)O(7) (n = 2) phases, the orbital ordering can be chiefly assigned to the d(x(2)-y(2)) orbital, in contrast with the zigzag-type d(z(2)) orbital ordering in the [Formula: see text] perovskite phase. Our theoretical analysis shows that a variety of essential factors, including the local structural distortions of the MnO(6) octahedra, the on-site Coulomb interaction, and magnetic interaction, have to be properly considered in order to achieve acceptable COO ground states for the layered variants in (La,Sr)(n+1)Mn(n)O(3n+1).
authors.affiliation: Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080, People's Republic of China.
authors.forename: C
authors.initials: C
authors.lastname: Ma
authors.forename: H X
authors.initials: HX
authors.lastname: Yang
authors.forename: L J
authors.initials: LJ
authors.lastname: Zeng
authors.forename: Z A
authors.initials: ZA
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: Y B
authors.initials: YB
authors.lastname: Qin
authors.forename: J Q
authors.initials: JQ
authors.lastname: Li