Effect of correlations and disorder on electron states in the Mott-Hubbard insulator V_2O_3
Abstract
We compare vanadium-deficient (nonstoichiometric) and titanium-doped vanadium sesquioxide through measurements of the electrical resistivity at a series of hydrostatic pressures, the magnetic susceptibility, and the low-temperature specific heat: all as a function of T. The pressure dependence of the critical temperature for this discontinuous metal-antiferromagnetic-insulator transition as well as the temperature dependence of the magnetic susceptibility track in the two cases. However, the pressure dependence of the Hubbard gap, the slower than exponential form of the low-temperature resistivity, and the concentration of two-level systems are markedly different for V_(1.9967)O_3 and (V_(0.99)Ti_(0.01))_2O_3. We discuss our results in terms of the intra-atomic Coulomb repulsion, which is of comparable magnitude to the bare bandwidth of the vanadium 3d states. The band splitting in the antiferromagnetic insulating state is argued to cross over to a Slater-type splitting between the subbands narrowed by correlations with a sufficient degree of oxygen nonstoichiometry or Ti doping.
Additional Information
© 1991 The American Physical Society. Received 25 June 1990. The work at The University of Chicago was supported by National Science Foundation (NSF) Grant No. DMR 8816817. J. Yang acknowledges support from NSF Grant No. DMR 8351992. The Purdue effort was supported by NSF Grant No. DMR 8616533. J. Spalek acknowledges the support of the Superconductivity Center at Purdue. We are most grateful to Patricia Metcalf for reannealing the crystals used in this research.Attached Files
Published - PhysRevB.43.607.pdf
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Additional details
- Alternative title
- Effect of correlations and disorder on electron states in the Mott-Hubbard insulator V2O3
- Eprint ID
- 47022
- Resolver ID
- CaltechAUTHORS:20140707-163038611
- NSF
- DMR 8816817
- NSF
- DMR 8351992
- NSF
- DMR 8616533
- Superconductivity Center, Purdue
- Created
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2014-07-09Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field