title: Evidence for Ionic Liquid Gate-Induced Metallization of Vanadium Dioxide Bars over Micron Length Scales.
abstract: It has recently been shown that the metal-insulator transition in vanadium dioxide epitaxial films can be suppressed and the material made metallic to low temperatures by ionic liquid gating due to migration of oxygen. The gating is only possible on certain crystal facets where volume channels along the VO2's rutile c-axis intersect the surface. Here, we fabricate bars with the c-axis in plane and oriented parallel to or perpendicular to the length of the bars. We show that only bars with the c-axis perpendicular to the bars, for which the volume channels are accessible from the sides of the bar, can be metallized by ionic liquid gating. Moreover, we find that bars up to at least 0.5 μm wide can be fully gated, demonstrating the possibility of the electric field induced migration of oxygen over very long distances, ∼5 times longer than previously observed.
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.|Max Plank Institute for Microstructure Physics , Weinberg 2, 06120 Halle (Saale), Germany.
authors.forename: Donata
authors.initials: D
authors.lastname: Passarello
authors.affiliation: Max Plank Institute for Microstructure Physics , Weinberg 2, 06120 Halle (Saale), Germany.
authors.forename: Simone G
authors.initials: SG
authors.lastname: Altendorf
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.
authors.forename: Jaewoo
authors.initials: J
authors.lastname: Jeong
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.
authors.forename: Charles
authors.initials: C
authors.lastname: Rettner
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.
authors.forename: Noel
authors.initials: N
authors.lastname: Arellano
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.
authors.forename: Teya
authors.initials: T
authors.lastname: Topuria
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.
authors.forename: Mahesh G
authors.initials: MG
authors.lastname: Samant
authors.affiliation: IBM Research - Almaden , San Jose, California 95120, United States.|Max Plank Institute for Microstructure Physics , Weinberg 2, 06120 Halle (Saale), Germany.
authors.forename: Stuart S P
authors.identifier: 0000-0003-4702-6139
authors.initials: SSP
authors.lastname: Parkin
keywords: Metal insulator transition; epitaxial oxide films; ionic liquid gating; metallization; vanadium dioxide