title: Pressure-Temperature Phase Diagram of Vanadium Dioxide.
abstract: The complexity of strongly correlated electron physics in vanadium dioxide is exemplified as its rich phase diagrams of all kinds, which in turn shed light on the mechanisms behind its various phase transitions. In this work, we map out the hydrostatic pressure-temperature phase diagram of vanadium dioxide nanobeams by independently varying pressure and temperature with a diamond anvil cell. In addition to the well-known insulating M1 (monoclinic) and metallic R (tetragonal) phases, the diagram identifies the existence at high pressures of the insulating M1' (monoclinic, more conductive than M1) phase and two metallic phases of X (monoclinic) and O (orthorhombic, at high temperature only). Systematic optical and electrical measurements combined with density functional calculations allow us to delineate their phase boundaries as well as reveal some basic features of the transitions.
authors.forename: Yabin
authors.initials: Y
authors.lastname: Chen
authors.forename: Shuai
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Shanghai 201203, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Ke
authors.forename: Changhyun
authors.initials: C
authors.lastname: Ko
authors.forename: Sangwook
authors.initials: S
authors.lastname: Lee
authors.affiliation: State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Tsinghua University , Beijing 100084, China.
authors.forename: Kai
authors.identifier: 0000-0002-0638-5189
authors.initials: K
authors.lastname: Liu
authors.affiliation: Center for High Pressure Science and Technology Advanced Research , Shanghai 201203, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Chen
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Joel W
authors.initials: JW
authors.lastname: Ager
authors.forename: Raymond
authors.initials: R
authors.lastname: Jeanloz
authors.affiliation: Materials Design SARL , 92120 Montrouge, France.
authors.forename: Volker
authors.initials: V
authors.lastname: Eyert
authors.affiliation: Materials Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
authors.forename: Junqiao
authors.identifier: 0000-0002-1498-0148
authors.initials: J
authors.lastname: Wu
keywords: VO2; diamond anvil cell; hydrostatic pressure; phase diagram; phase transition