title: Novel high-pressure monoclinic metallic phase of V2O3.
abstract: Vanadium sesquioxide, V2O3, is a prototypical metal-to-insulator system where, in temperature-dependent studies, the transition always coincides with a corundum-to-monoclinic structural transition. As a function of pressure, V2O3 follows the expected behavior of increased metallicity due to a larger bandwidth for pressures up to 12.5 GPa. Surprisingly, for higher pressures when the structure becomes unstable, the resistance starts to increase. Around 32.5 GPa at 300 K, we observe a novel pressure-induced corundum-to-monoclinic transition between two metallic phases, showing that the structural phase transition can be decoupled from the metal-insulator transition. Using x-ray Raman scattering, we find that screening effects, which are strong in the corundum phase, become weakened at high pressures. Theoretical calculations indicate that this can be related to a decrease in coherent quasiparticle strength, suggesting that the high-pressure phase is likely a critical correlated metal, on the verge of Mott-insulating behavior.
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Ding
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Cheng-Chien
authors.initials: CC
authors.lastname: Chen
authors.affiliation: Geological and Environmental Sciences, Stanford University, Stanford, California 94305, USA.
authors.forename: Qiaoshi
authors.initials: Q
authors.lastname: Zeng
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors.forename: Heung-Sik
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Republic of Korea.
authors.forename: Myung Joon
authors.initials: MJ
authors.lastname: Han
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Balasubramanian
authors.affiliation: PNCSRF, APS Sector 20, Argonne, Illinois 60439, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Gordon
authors.affiliation: HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA and State Key Lab of Superhard Materials, Jilin University, Changchun 130012, China.
authors.forename: Fangfei
authors.initials: F
authors.lastname: Li
authors.affiliation: HiPSEC and Department of Physics, University of Nevada Las Vegas, Las Vegas, Nevada, 89154, USA.
authors.forename: Ligang
authors.initials: L
authors.lastname: Bai
authors.affiliation: HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
authors.forename: Dimitry
authors.initials: D
authors.lastname: Popov
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Steve M
authors.initials: SM
authors.lastname: Heald
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gog
authors.affiliation: HPSynC, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA and HPCAT, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA and Geophysical Laboratory, Carnegie Institution of Washington, Washington, D.C. 20015, USA and Center for High Pressure Science and Technology Advanced Research, 1690 Cailun Road, Pudong, Shanghai 201203, China.
authors.forename: Ho-kwang
authors.initials: HK
authors.lastname: Mao
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA and Department of Physics, Northern Illinois University, De Kalb, Illinois 60115, USA.
authors.forename: Michel
authors.initials: M
authors.lastname: van Veenendaal