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Title: Investigation of the Presence of Charge Order in Magnetite by Measurement of the Sprin Wave Spectrum

Abstract

Inelastic neutron scattering results on magnetite (Fe{sub 3}O{sub 4}) show a large splitting in the acoustic spin wave branch, producing a 7 meV gap midway to the Brillouin zone boundary at q = (0,0,1/2) and {h_bar}{omega} = 43 meV. The splitting occurs below the Verwey transition temperature, where a metal-insulator transition occurs simultaneously with a structural transformation, supposedly caused by the charge ordering on the iron sublattice. The wavevector (0,0,1/2) corresponds to the superlattice peak in the low symmetry structure. The dependence of the magnetic superexchange on changes in the crystal structure and ionic configurations that occur below the Verwey transition affect the spin wave dispersion. To better understand the origin of the observed splitting, several Heisenberg models intended to reproduce the pair-wise variation of the magnetic superexchange arising from both small crystalline distortions and charge ordering were studied. None of the models studied predicts the observed splitting, whose origin may arise from charge-density wave formation or magnetoelastic coupling.

Authors:
 [1];  [2];  [3];  [4];  [5];  [6]
  1. Ames Laboratory
  2. ORNL
  3. University of Missouri, Columbia
  4. Brookhaven National Laboratory (BNL)
  5. Purdue University
  6. University of Purdue
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); High Flux Isotope Reactor
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1042711
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review B; Journal Volume: 73; Journal Issue: 17
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ACOUSTICS; BRILLOUIN ZONES; CHARGE DENSITY; CRYSTAL STRUCTURE; HEISENBERG MODEL; IRON; MAGNETITE; NEUTRON DIFFRACTION; INELASTIC SCATTERING; SPIN WAVES; SUPERLATTICES; SYMMETRY; TRANSITION TEMPERATURE

Citation Formats

McQueeny, R. J., Yethiraj, Mohana, Montfrooij, W., Garner, J. S., Metcalf, P., and Honig, J. M. Investigation of the Presence of Charge Order in Magnetite by Measurement of the Sprin Wave Spectrum. United States: N. p., 2006. Web. doi:10.1103/PhysRevB.73.174409.
McQueeny, R. J., Yethiraj, Mohana, Montfrooij, W., Garner, J. S., Metcalf, P., & Honig, J. M. Investigation of the Presence of Charge Order in Magnetite by Measurement of the Sprin Wave Spectrum. United States. doi:10.1103/PhysRevB.73.174409.
McQueeny, R. J., Yethiraj, Mohana, Montfrooij, W., Garner, J. S., Metcalf, P., and Honig, J. M. Sun . "Investigation of the Presence of Charge Order in Magnetite by Measurement of the Sprin Wave Spectrum". United States. doi:10.1103/PhysRevB.73.174409.
@article{osti_1042711,
title = {Investigation of the Presence of Charge Order in Magnetite by Measurement of the Sprin Wave Spectrum},
author = {McQueeny, R. J. and Yethiraj, Mohana and Montfrooij, W. and Garner, J. S. and Metcalf, P. and Honig, J. M.},
abstractNote = {Inelastic neutron scattering results on magnetite (Fe{sub 3}O{sub 4}) show a large splitting in the acoustic spin wave branch, producing a 7 meV gap midway to the Brillouin zone boundary at q = (0,0,1/2) and {h_bar}{omega} = 43 meV. The splitting occurs below the Verwey transition temperature, where a metal-insulator transition occurs simultaneously with a structural transformation, supposedly caused by the charge ordering on the iron sublattice. The wavevector (0,0,1/2) corresponds to the superlattice peak in the low symmetry structure. The dependence of the magnetic superexchange on changes in the crystal structure and ionic configurations that occur below the Verwey transition affect the spin wave dispersion. To better understand the origin of the observed splitting, several Heisenberg models intended to reproduce the pair-wise variation of the magnetic superexchange arising from both small crystalline distortions and charge ordering were studied. None of the models studied predicts the observed splitting, whose origin may arise from charge-density wave formation or magnetoelastic coupling.},
doi = {10.1103/PhysRevB.73.174409},
journal = {Physical Review B},
number = 17,
volume = 73,
place = {United States},
year = {Sun Jan 01 00:00:00 EST 2006},
month = {Sun Jan 01 00:00:00 EST 2006}
}