title: Ferro-type orbital state in the Mott transition system Ca2-xSrxRuO4 studied by the resonant x-ray scattering interference technique.
abstract: We have succeeded in detecting ferro-type orbital states in Ca2-xSrxRuO4, which is the first outcome in a 4d Mott transition system by the resonant x-ray scattering interference technique. For x=0 (Mott insulator), the resonant signal for d(xy) orbital ordering is observed even at room temperature, in which the Jahn-Teller distortion is negligible. The signal disappears near the metal-insulator transition. On the other hand, in a metallic phase for x=0.5, orbital polarization with d(yz/zx) character dominates. With lowering temperature, the magnitude of the resonant signal slightly decreases owing to the additional influence of the gamma band with d(xy) character.
authors.affiliation: Photon Factory, IMSS, High Energy Accelerator Research Organization (KEK), Tsukuba, 305-0801, Japan. masato.kubota@kek.jp
authors.forename: M
authors.initials: M
authors.lastname: Kubota
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: M
authors.initials: M
authors.lastname: Mizumaki
authors.forename: H
authors.initials: H
authors.lastname: Ohsumi
authors.forename: N
authors.initials: N
authors.lastname: Ikeda
authors.forename: S
authors.initials: S
authors.lastname: Nakatsuji
authors.forename: H
authors.initials: H
authors.lastname: Fukazawa
authors.forename: Y
authors.initials: Y
authors.lastname: Maeno