Optical conductivity of V4O7 across its metal-insulator transition
arXiv:1407.1081 · doi:10.1103/PhysRevB.90.115149
Abstract
The optical properties of a V4O7 single crystal have been investigated from the high temperature metallic phase down to the low temperature antiferromagnetic insulating one. The temperature dependent behavior of the optical conductivity across the metal-insulator transition (MIT) can be explained in a polaronic scenario. Charge carriers form strongly localized polarons in the insulating phase as suggested by a far-infrared charge gap abruptly opening at T_MIT = 237 K. In the metallic phase instead the presence of a Drude term is indicative of fairly delocalized charges with a moderately renormalized mass m* = 5m_e. The electronic spectral weight is almost recovered on an energy scale of 1 eV, which is much narrower compared to VO2 and V2O3 cases. Those findings suggest that electron-lattice interaction rather than electronic correlation is the driving force for V4O7 metal-insulator transition.
5 pages, 3 figures
References in corpus (6)
- Electrodynamics of the vanadium oxides VO2 and V2O3
- Electron-phonon interaction and charge carrier mass enhancement in SrTiO3
- A Microscopic View on the Mott transition in Chromium-doped V2O3
- Quasiparticle evolution and pseudogap formation in V2O3: An infrared spectroscopy study
- Electrodynamics near the Metal-to-Insulator Transition in V3O5
- Optical Properties of (SrMnO3)n/(LaMnO3)2n superlattices: an insulator-to-metal transition observed in the absence of disorder