Emergence of metallic monoclinic states of VO${}_2$ films induced by K deposition

Abstract

In order to study the origin of metallization of VO${}_2$ induced by electron injection, we deposit K atoms onto the surface of VO${}_2$ films grown on TiO${}_2$ (001) substrates, and we investigate the change in the electronic and crystal structures using $insitu$ photoemission spectroscopy and x-ray absorption spectroscopy (XAS). The deposition of K atoms onto a surface of insulating monoclinic VO${}_2$ leads to a phase transition from insulator to metal. In this metallization state, the V-V dimerization characteristic to the monoclinic phase of VO${}_2$ still exists, as revealed by the polarization dependence of the XAS spectra. Furthermore, the monoclinic metal undergoes a transition to a monoclinic insulator with decrease in temperature, and to a rutile metal with increase in temperature. These results indicate the existence of a metallic monoclinic phase around the boundary between the insulating monoclinic and metallic rutile phases in the case of electron-doped VO${}_2$.

20 pages, 5 figures

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Cited by in corpus (5)

• Mott switching and structural transition in the metal phase of $V{O}_2$ nanodomain
• Thickness dependence of electronic and crystal structures in VO${}_2$ ultrathin films: suppression of the collaborative Mott-Peierls transition
• Massively strained VO2 thin film growth on RuO2
• Electronic phase diagram of Cr-doped VO2 epitaxial films studied by in situ photoemission spectroscopy
• Interface-induced collective phase transition in VO2-based bilayers studied by layer selective spectroscopy