title: Crystal-facet-dependent metallization in electrolyte-gated rutile TiO2 single crystals.
abstract: The electric-field-induced metallization of insulating oxides is a powerful means of exploring and creating exotic electronic states. Here we show by the use of ionic liquid gating that two distinct facets of rutile TiO2, namely, (101) and (001), show clear evidence of metallization, with a disorder-induced metal-insulator transition at low temperatures, whereas two other facets, (110) and (100), show no substantial effects. This facet-dependent metallization can be correlated with the surface energy of the respective crystal facet and, thus, is consistent with oxygen vacancy formation and diffusion that results from the electric fields generated within the electric double layers at the ionic liquid/TiO2 interface. These effects take place at even relatively modest gate voltages.
authors: IBM Almaden Research Center , San Jose, California 95120, United States.
authors: Thomas D
authors: TD
authors: Schladt
authors: Tanja
authors: T
authors: Graf
authors: Nagaphani B
authors: NB
authors: Aetukuri
authors: Mingyang
authors: M
authors: Li
authors: Andrea
authors: A
authors: Fantini
authors: Xin
authors: X
authors: Jiang
authors: Mahesh G
authors: MG
authors: Samant
authors: Stuart S P
authors: SS
authors: Parkin