Orbital superexchange and crystal field simultaneously at play in YVO 3

• Verfasst von: Benckiser, Eva [VerfasserIn]
• Verfasst von: Schmitt, Thomas [VerfasserIn]
• Verfasst von: Haverkort, Maurits W. [VerfasserIn]
• Titel: Orbital superexchange and crystal field simultaneously at play in YVO 3
• Titelzusatz: resonant inelastic x-ray scattering at V L edge and the O K edge
• Verf.angabe: E. Benckiser, L. Fels, G. Ghiringhelli, M. Moretti Sala, T. Schmitt, J. Schlappa, V.N. Strocov, N. Mufti, G.R. Blake, A.A. Nugroho, T.T.M. Palstra, M.W. Haverkort, K. Wohlfeld, and M. Grüninger
• Fussnoten: Gesehen am 04.10.2017 ; Die Ziffer 3 im Titel ist tiefgestellt
• Titel Quelle: Enthalten in: Physical review / B
• Jahr Quelle: 2013
• Band/Heft Quelle: 88(2013,20), Artikel-Nummer 205115, 13 Seiten
• ISSN Quelle: 1550-235X
• DOI: doi:10.1103/PhysRevB.88.205115
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1564050637

Abstract

We report on the observation of orbital excitations in YVO3 by means of resonant inelastic x-ray scattering (RIXS) at energies across the vanadium L3 and oxygen K absorption edges. At the V L3 edge, we are able to resolve the full spectrum of orbital excitations up to 5 eV. In order to unravel the effect of superexchange interactions and the crystal field on the orbital excitations, we analyzed the energy and temperature dependence of the intra-t2g excitations at 0.1-0.2 eV in detail. While these results suggest a dominant influence of the crystal field, peak shifts of about 13-20 meV observed as a function of the transferred momentum q∥a reflect a finite dispersion of the orbital excitations. This is puzzling since theoretical models based on superexchange interactions predict a dispersion only for q∥c. Furthermore, we demonstrate that RIXS at the O K edge is very sensitive to intersite excitations. At the O K edge, we observe excitations across the Mott-Hubbard gap and an additional feature at 0.4 eV, which we attribute to two-orbiton scattering, i.e., an exchange of orbitals between adjacent sites. Altogether, our results indicate that both superexchange interactions and the crystal field are important for a quantitative understanding of the orbital excitations in YVO3.