title: Robustness of basal-plane antiferromagnetic order and the J(eff)=1/2 state in single-layer iridate spin-orbit Mott insulators.
abstract: The magnetic structure and electronic ground state of the layered perovskite Ba(2)IrO(4) have been investigated using x-ray resonant magnetic scattering. Our results are compared with those for Sr(2)IrO(4), for which we provide supplementary data on its magnetic structure. We find that the dominant, long-range antiferromagnetic order is remarkably similar in the two compounds and that the electronic ground state in Ba(2)IrO(4), deduced from an investigation of the x-ray resonant magnetic scattering L(3)/L(2) intensity ratio, is consistent with a J(eff)=1/2 description. The robustness of these two key electronic properties to the considerable structural differences between the Ba and Sr analogues is discussed in terms of the enhanced role of the spin-orbit interaction in 5d transition metal oxides.
authors.affiliation: London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom and Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Boseggia
authors.affiliation: Royal Commission for the Exhibition of 1851 Research Fellow, Interface Analysis Centre, University of Bristol, Bristol BS2 8BS, United Kingdom.
authors.forename: R
authors.initials: R
authors.lastname: Springell
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany.
authors.forename: H C
authors.initials: HC
authors.lastname: Walker
authors.affiliation: Laboratory for Quantum Magnetism, ICMP, École Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: H M
authors.initials: HM
authors.lastname: Rønnow
authors.affiliation: Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland and DPMC-MaNEP, University of Geneva, CH-1211 Geneva, Switzerland.
authors.forename: Ch
authors.initials: Ch
authors.lastname: Rüegg
authors.affiliation: National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Okabe
authors.affiliation: National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Isobe
authors.affiliation: Scottish Universities Physics Alliance, School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: R S
authors.initials: RS
authors.lastname: Perry
authors.affiliation: Diamond Light Source Ltd, Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire OX11 0DE, United Kingdom.
authors.forename: S P
authors.initials: SP
authors.lastname: Collins
authors.affiliation: London Centre for Nanotechnology and Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom.
authors.forename: D F
authors.initials: DF
authors.lastname: McMorrow