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arXiv · 0805.1653

Charge dynamics in thermally and doping induced insulator-metal transitions of (Ti1-xVx)2O3

M. Uchida·J. Fujioka·Y. Onose·Y. Tokura
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Abstract

Charge dynamics of (Ti1-xVx)2O3 with x=0-0.06 has been investigated by measurements of charge transport and optical conductivity spectra in a wide temperature range of 2-600K with the focus on the thermally and doping induced insulator-metal transitions (IMTs). The optical conductivity peaks for the interband transitions in the 3d t2g manifold are observed in the both insulating and metallic states, while their large variation (by ~0.4 eV) with change of temperature and doping level scales with that of the Ti-Ti dimer bond length, indicating the weakened singlet bond in the course of IMTs. The thermally and V-doping induced IMTs are driven with the increase in carrier density by band-crossing and hole-doping, respectively, in contrast to the canonical IMT of correlated oxides accompanied by the whole collapse of the Mott gap.

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M. Uchida, J. Fujioka, Y. Onose, Y. Tokura. 2008-05-12. Charge dynamics in thermally and doping induced insulator-metal transitions of (Ti1-xVx)2O3. https://doi.org/10.1103/physrevlett.101.066406

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