Berlin 2015 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 100: Correlated Electrons: Other Materials
TT 100.10: Vortrag
Donnerstag, 19. März 2015, 17:30–17:45, H 3005
Ground state oxygen holes and the metal-insulator transition in rare earth nickelates — •Thorsten Schmitt1, Valentina Bisogni1, Sara Catalano2, Marta Gibert2, Raoul Scherwitzl2, Yaobo Huang1, Vladimir Strocov1, Pavlo Zubko2, Robert J. Green3, Shadi Balandeh3, George Sawatzky3, and Jean-Marc Triscone2 — 1Research Department Synchrotron Radiation and Nanotechnology, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland — 2Département de Physique de la Matière Condensée, University of Geneva, Switzerland — 3Department of Physics and Astronomy, University of British Columbia, Vancouver, Canada
Perovskite rare-earth (Re) nickelates ReNiO3 continue to attract a lot of interest owing to their intriguing properties like a sharp metal to insulator transition (MIT), unusual magnetic order [1] and expected superconductivity in specifically tuned super-lattices [2]. Full understanding of these materials, however, is hampered by the difficulties in describing their electronic ground state (GS). From X-ray absorption (XAS) at the Ni 2p3/2 edge of thin films of NdNiO3 and corresponding RIXS maps vs. incident and transferred photon energies we reveal that the electronic GS configuration of NdNiO3 is composed of delocalized and localized components. Our study conveys that a Ni 3d8-like configuration with holes at oxygen takes on the leading role in the GS and the MIT of ReNiO3 as proposed by recent model theories [3].
[1] Medarde et al., J. Phys. Cond. Matt. 9, 1679 (1997).
[2] Chaloupka et al., PRL 100, 016404 (2008).
[3] Mizokawa et al., PRB 61, 11263 (2000);
Park et al., PRL 109, 156402 (2012).