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Hybridization, superexchange, and competing magnetoelastic interactions in TiOBr

Macovez, Roberto; Luzon, Javier; Schiessling, Joachim; Sadoc, Aymeric; Kjeldgaard, Lisbeth LU ; van Smaalen, Sander; Fausti, Daniele; van Loosdrecht, Paul H. M.; Broer, Ria and Rudolf, Petra (2007) In Physical Review B (Condensed Matter and Materials Physics) 76(20).
Abstract
A crystalline sample of TiOBr is probed at room temperature by a combination of electron spectroscopies and the results are compared to theoretical embedded-cluster calculations. Resonant photoemission of the valence band confirms that the lowest binding energy feature arises from the singly occupied Ti 3d orbital. The polarization dependence of this orbital in nonresonant photoemission is consistent with the expected dominant d(y)(2)-z(2) character. The analysis of the Ti L-2,L-3 x-ray absorption spectra confirms the complete splitting of the Ti 3d shell. X-ray absorption and resonant photoemission at the O 1s edge provide direct evidence for hybridization between the transition metal orbitals and the O 2p levels, which leads to... (More)
A crystalline sample of TiOBr is probed at room temperature by a combination of electron spectroscopies and the results are compared to theoretical embedded-cluster calculations. Resonant photoemission of the valence band confirms that the lowest binding energy feature arises from the singly occupied Ti 3d orbital. The polarization dependence of this orbital in nonresonant photoemission is consistent with the expected dominant d(y)(2)-z(2) character. The analysis of the Ti L-2,L-3 x-ray absorption spectra confirms the complete splitting of the Ti 3d shell. X-ray absorption and resonant photoemission at the O 1s edge provide direct evidence for hybridization between the transition metal orbitals and the O 2p levels, which leads to superexchange interactions between the Ti ions. The existence of a mixing of O and Ti states and of strong superexchange interactions is supported by calculations of the ground-state electronic and magnetic properties. The calculated superexchange interchain interaction is one fifth in strength of the total magnetic coupling along the chain, and is antiferromagnetic in character. This O-mediated interchain interaction is frustrated in the room temperature phase of TiOBr and thus couples strongly to distortions of the soft lattice. The competition between the interchain magnetoelastic coupling and the spin-Peierls interaction might be at the origin of the complex TiOX phase diagram. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B (Condensed Matter and Materials Physics)
volume
76
issue
20
publisher
American Physical Society
external identifiers
  • wos:000251326900028
  • scopus:36348931461
ISSN
1098-0121
DOI
10.1103/PhysRevB.76.205111
language
English
LU publication?
yes
id
3dc0df79-b55e-4bde-8a35-071e718695a0 (old id 968565)
date added to LUP
2008-01-30 12:42:04
date last changed
2017-07-30 04:33:02
@article{3dc0df79-b55e-4bde-8a35-071e718695a0,
  abstract     = {A crystalline sample of TiOBr is probed at room temperature by a combination of electron spectroscopies and the results are compared to theoretical embedded-cluster calculations. Resonant photoemission of the valence band confirms that the lowest binding energy feature arises from the singly occupied Ti 3d orbital. The polarization dependence of this orbital in nonresonant photoemission is consistent with the expected dominant d(y)(2)-z(2) character. The analysis of the Ti L-2,L-3 x-ray absorption spectra confirms the complete splitting of the Ti 3d shell. X-ray absorption and resonant photoemission at the O 1s edge provide direct evidence for hybridization between the transition metal orbitals and the O 2p levels, which leads to superexchange interactions between the Ti ions. The existence of a mixing of O and Ti states and of strong superexchange interactions is supported by calculations of the ground-state electronic and magnetic properties. The calculated superexchange interchain interaction is one fifth in strength of the total magnetic coupling along the chain, and is antiferromagnetic in character. This O-mediated interchain interaction is frustrated in the room temperature phase of TiOBr and thus couples strongly to distortions of the soft lattice. The competition between the interchain magnetoelastic coupling and the spin-Peierls interaction might be at the origin of the complex TiOX phase diagram.},
  author       = {Macovez, Roberto and Luzon, Javier and Schiessling, Joachim and Sadoc, Aymeric and Kjeldgaard, Lisbeth and van Smaalen, Sander and Fausti, Daniele and van Loosdrecht, Paul H. M. and Broer, Ria and Rudolf, Petra},
  issn         = {1098-0121},
  language     = {eng},
  number       = {20},
  publisher    = {American Physical Society},
  series       = {Physical Review B (Condensed Matter and Materials Physics)},
  title        = {Hybridization, superexchange, and competing magnetoelastic interactions in TiOBr},
  url          = {http://dx.doi.org/10.1103/PhysRevB.76.205111},
  volume       = {76},
  year         = {2007},
}