title: X-ray Absorption Spectroscopy Study of the Effect of Rh doping in Sr2IrO4.
abstract: We investigate the effect of Rh doping in Sr2IrO4 using X-ray absorption spectroscopy (XAS). We observed appearance of new electron-addition states with increasing Rh concentration (x in Sr2Ir1-xRhxO4) in accordance with the concept of hole doping. The intensity of the hole-induced state is however weak, suggesting weakness of charge transfer (CT) effect and Mott insulating ground states. Also, Ir Jeff = 1/2 upper Hubbard band shifts to lower energy as x increases up to x = 0.23. Combined with optical spectroscopy, these results suggest a hybridisation-related mechanism, in which Rh doping can weaken the (Ir Jeff = 1/2)-(O 2p) orbital hybridisation in the in-planar Rh-O-Ir bond networks.
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
authors.forename: C H
authors.initials: CH
authors.lastname: Sohn
authors.affiliation: IPIT &Department of Physics, Chonbuk National University, Jeonju 54896, Korea.
authors.forename: Deok-Yong
authors.initials: DY
authors.lastname: Cho
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
authors.forename: C-T
authors.initials: CT
authors.lastname: Kuo
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
authors.forename: L J
authors.initials: LJ
authors.lastname: Sandilands
authors.affiliation: Center for Advanced Materials, Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.forename: T F
authors.initials: TF
authors.lastname: Qi
authors.affiliation: Center for Advanced Materials, Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506, USA.
authors.forename: G
authors.initials: G
authors.lastname: Cao
authors.affiliation: Center for Correlated Electron Systems, Institute for Basic Science (IBS), Seoul 08826, Korea.|Department of Physics and Astronomy, Seoul National University, Seoul 08826, Korea.
authors.forename: T W
authors.initials: TW
authors.lastname: Noh