Photoemission study of the metal-insulator transition in VO 2/TiO2(001): Evidence for strong electron-electron and electron-phonon interaction

K. Okazaki, H. Wadati, A. Fujimori, M. Onoda, Yuji Muraoka, Z. Hiroi

Research output: Contribution to journalArticle

93 Citations (Scopus)

Abstract

We have made a detailed temperature-dependent photoemission study of VO2/TiO2(001) thin films, which show a metal-insulator transition at ∼300 K. Clean surfaces were obtained by annealing the films in an oxygen atmosphere. Spectral weight transfer between the coherent and incoherent parts accompanying the metal-insulator transition was clearly observed. We also observed a hysteretic behavior of the spectra for heating-cooling cycles. We have derived the "bulk" spectrum of the metallic phase and found that it has a strong incoherent part. The width of the coherent part is comparable to that given by band-structure calculation in spite of its reduced spectral weight, indicating that the momentum dependence of the self-energy is significant. This is attributed to by ferromagnetic fluctuation arising from Hund's rule coupling between different d orbitals as originally proposed by Zylbersztejn and Mott. In the insulating phase, the width of the V 3d band shows strong temperature dependence. We attribute this to electron-phonon interaction and have reproduced it using the independent boson model with a very large coupling constant.

Original languageEnglish
Article number165104
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume69
Issue number16
DOIs
Publication statusPublished - Apr 2004
Externally publishedYes

Fingerprint

Electron-phonon interactions
Metal insulator transition
Photoemission
electron phonon interactions
photoelectric emission
insulators
Bosons
Electrons
Band structure
metals
Momentum
electrons
bosons
Annealing
Oxygen
Cooling
momentum
cooling
Heating
atmospheres

ASJC Scopus subject areas

  • Condensed Matter Physics

Cite this

Photoemission study of the metal-insulator transition in VO 2/TiO2(001) : Evidence for strong electron-electron and electron-phonon interaction. / Okazaki, K.; Wadati, H.; Fujimori, A.; Onoda, M.; Muraoka, Yuji; Hiroi, Z.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 69, No. 16, 165104, 04.2004.

Research output: Contribution to journalArticle

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