Transport properties around the metal-insulator transition for SrVO3 ultrathin films fabricated by electrochemical etching

By using electrochemical etching, we fabricated conductive ultrathin SrVO3\n(SVO) films that exhibited metallic behavior down to 3 monolayers (ML). From an\nobserved systematic change in transport properties with decreasing film\nthickness, it was found that the disorder in the films remained nearly\nunchanged during etching, and only the thickness was reduced. This is in\ncontrast to the insulating behavior found for as-deposited SVO ultrathin films.\nFor the etched films, the electron mobility at 200 K decreased with decreasing\nfilm thickness below 10 ML, originating from an increased scattering rate and\nelectron effective mass near the metal-insulator transition. A slight upturn in\nthe resistivity and a positive magnetoresistance at low temperatures were\ntypically observed for the etched films down to 3 ML, which was explained by\nweak anti-localization of electrons in a weakly disordered metal.\n