Role of disorder and correlations in metal-insulator transition in ultrathin SrVO3 films

Abstract

Metallic oxide SrVO3 represents a prototype system for the study of the mechanism behind thickness-induced metal-to-insulator transition (MIT) or crossover in thin films due to its simple cubic symmetry with one electron in the 3d state in the bulk. Here we report a deviation of chemical composition and distortion of lattice structure existing in the initial 3 unit cells of SrVO3 films grown on SrTiO3 (001) from its bulk form, which shows a direct correlation to the thickness-dependent MIT. In-situ photoemission and scanning tunneling spectroscopy indicate a MIT at the critical thickness of ~3 unit cell (u.c.), which coincides with the formation of a (root2Xroot2)R45 surface reconstruction. However, atomically resolved scanning transmission electron microscopy and electron energy loss spectroscopy show depletion of Sr, change of V valence, thus implying the existence of a significant amount of oxygen vacancies in the 3 u.c. of SrVO3 near the interface. Transport and magneto-transport measurements further reveal that disorder, rather than electron correlations, is likely to be the main cause for the MIT in the SrVO3 ultrathin films.

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• Multiferroicity, The coupling between magnetic and polarization
• The role of oxygen vacancies in SrTiO3 at the LaAlO3/SrTiO3 interface
• Strain controlled oxygen vacancy formation and ordering in CaMnO${}_3$
• Metal-insulator transition in ultrathin LaNiO3 films
• Electronics with correlated oxides: SrVO${}_3$/SrTiO${}_3$ as a Mott transistor
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Cited by in corpus (11)

• Mott-Anderson Metal-Insulator Transitions from Entanglement
• Mesoscopic transport signatures of disorder-induced non-Hermitian phases
• Quantum Confinement Induced Metal-Insulator Transition in Strongly Correlated Quantum Wells of SrVO${}_3$ Superlattice
• Bandwidth Control and Symmetry Breaking in a Mott-Hubbard Correlated Metal
• Zoology of spin and orbital fluctuations in ultrathin oxide films
• Effects of Temperature and Magnetization on the Mott-Anderson Physics in one-dimensional Disordered Systems
• Visualizing quantum phenomena at complex oxide interfaces: an atomic view from scanning transmission electron microscopy
• Electron-vacancy scattering in SrNbO${}_3$ and SrTiO${}_3$: A DFT-NEGF study
• Transport properties around the metal-insulator transition for SrVO3 ultrathin films fabricated by electrochemical etching
• Tuning Structural, Transport and Magnetic Properties of Epitaxial SrRuO3 through Ba-Substitution
• Large Rashba parameter for 4d strongly correlated perovskite oxide SrNbO3 ultrathin films