The change in electronic structure of V1-xWxO 2 thin films across a metal-insulator transition (MIT) is investigated in terms of hard x-ray photoemission spectroscopy and x-ray absorption spectroscopy. In the lower doping range (0 ≤ x ≤ 0.08), the spectra exhibit the characteristic features for the dimerization of V ions in the monoclinic phase, indicating that Peierls-like instability predominately causes the MIT in this range. Conversely, in the higher doping range (0.1 ≤ x), spectral weight transfer is observed from the coherent part at the Fermi level to the incoherent part, indicating that the ground state of V 1-xWxO2 films in this range is a typical Mott insulator. The results suggest that the unusual phase diagram of the V 1-xWxO2 thin films originates from the competition between the Peierls and Mott instabilities.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2011 Nov 28|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics