title: Understanding the nature of the kinetic process in a VO2 metal-insulator transition.
abstract: Understanding the kinetics during the metal-insulator transition process is crucial to sort out the underlying physical nature of electron-lattice interactions in correlated materials. Here, based on the temperature-dependent in situ x-ray absorption fine structure measurement and density-functional theory calculations, we have revealed that the monoclinic-to-tetragonal phase transition of VO2 near the critical temperature is characterized by a sharp decrease of the twisting angle δ of the nearest V-V coordination. The VO2 metallization occurs in the intermediate monoclinic like structure with a large twist of V-V pairs when the δ angle is smaller than 1.4°. The correlation between structural kinetics and electronic structure points out that the structural rearrangement is a key factor to narrow the insulating band gap.
authors.affiliation: National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, Anhui 230029, People’s Republic of China.
authors.forename: Tao
authors.initials: T
authors.lastname: Yao
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Zhang
authors.forename: Zhihu
authors.initials: Z
authors.lastname: Sun
authors.forename: Shoujie
authors.initials: S
authors.lastname: Liu
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Huang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xie
authors.forename: Changzheng
authors.initials: C
authors.lastname: Wu
authors.forename: Xun
authors.initials: X
authors.lastname: Yuan
authors.forename: Wenqing
authors.initials: W
authors.lastname: Zhang
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Wu
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Pan
authors.forename: Fengchun
authors.initials: F
authors.lastname: Hu
authors.forename: Lihui
authors.initials: L
authors.lastname: Wu
authors.forename: Qinghua
authors.initials: Q
authors.lastname: Liu
authors.forename: Shiqiang
authors.initials: S
authors.lastname: Wei