Please use this identifier to cite or link to this item: http://hdl.handle.net/10995/102235
Title: Magnetism and charge ordering in high- and low-temperature phases of Nb2O2F3
Authors: Gapontsev, V. V.
Khomskii, D. I.
Streltsov, S. V.
Issue Date: 2016
Publisher: Elsevier B.V.
Citation: Gapontsev V. V. Magnetism and charge ordering in high- and low-temperature phases of Nb2O2F3 / V. V. Gapontsev, D. I. Khomskii, S. V. Streltsov. — DOI 10.1016/j.jmmm.2016.06.084 // Journal of Magnetism and Magnetic Materials. — 2016. — Vol. 420. — P. 28-32.
Abstract: It is shown using ab initio band structure calculations that Nb2O2F3 is in the orbital-selective regime in the high-temperature phase (T>;90K), when two electrons occupy singlet molecular orbital, while the magnetic response comes from the remaining single electron in Nb23.5+ dimer. The charge order occurs at low temperatures, resulting in the formation of Nb3+–Nb3+ and Nb4+–Nb4+ dimers, which makes this system nonmagnetic. The single electron with unpaired spin is transferred to Nb3+–Nb3+ dimer, but due to a strong splitting of the bonding xz/yz molecular orbitals the low-spin state with S=0 is stabilized. We argue that the mechanism of the charge ordering in Nb2O2F3 is the gain in kinetic energy related to the formation of molecular orbitals, which occurs due to a strong nonlinear distance dependence of the hopping parameters. © 2016 Elsevier B.V.
Keywords: CHARGE ORDERING
DIMERS
CALCULATIONS
KINETIC ENERGY
KINETICS
MOLECULAR ORBITALS
TEMPERATURE
AB INITIO BAND STRUCTURE
CHARGE ORDERING
HIGH TEMPERATURE PHASE
HOPPING PARAMETERS
LOW TEMPERATURE PHASIS
LOW TEMPERATURES
MAGNETIC RESPONSE
SINGLE ELECTRON
DIMERS
URI: http://hdl.handle.net/10995/102235
Access: info:eu-repo/semantics/openAccess
SCOPUS ID: 84978254148
PURE ID: 1053494
7cc7b95c-0744-44d7-b038-a73f45b49622
ISSN: 3048853
DOI: 10.1016/j.jmmm.2016.06.084
Appears in Collections:Научные публикации, проиндексированные в SCOPUS и WoS CC

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