title: Mechanics and dynamics of the strain-induced M1-M2 structural phase transition in individual VO₂ nanowires.
abstract: The elastic properties and structural phase transitions of individual VO(2) nanowires were studied using an in situ push-to-pull microelectromechanical device to realize quantitative tensile analysis in a transmission electron microscope and a synchrotron X-ray microdiffraction beamline. A plateau was detected in the stress-strain curve, signifying superelasticity of the nanowire arising from the M1-M2 structural phase transition. The transition was induced and controlled by uniaxial tension. The transition dynamics were characterized by a one-dimensionally aligned domain structure with pinning and depinning of the domain walls along the nanowire. From the stress-strain dependence the Young's moduli of the VO(2) M1 and M2 phases were estimated to be 128 ± 10 and 156 ± 10 GPa, respectively. Single pinning and depinning events of M1-M2 domain wall were observed in the superelastic regime, allowing for evaluation of the domain wall pinning potential energy. This study demonstrates a new way to investigate nanoscale mechanics and dynamics of structural phase transitions in general.
authors: Department of Materials Science and Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
authors: Hua
authors: H
authors: Guo
authors: Kai
authors: K
authors: Chen
authors: Y
authors: Y
authors: Oh
authors: Kevin
authors: K
authors: Wang
authors: Catherine
authors: C
authors: Dejoie
authors: S A
authors: SA
authors: Syed Asif
authors: O L
authors: OL
authors: Warren
authors: Z W
authors: ZW
authors: Shan
authors: J
authors: J
authors: Wu
authors: A M
authors: AM
authors: Minor