title: Coexistence of multiple metastable polytypes in rhombohedral bismuth.
abstract: Derivative structural polytypes coexisting with the rhombohedral A7 structure of elemental bismuth (Bi) have been discovered at ambient condition, based on microstructure analyses of pure Bi samples treated under high pressure and high temperature conditions. Three structures with atomic positions close to those of the A7 structure have been identified through first-principles calculations, showing these polytypes energetically comparable to the A7 structure under ambient condition. Simulated diffraction data are in excellent agreement with the experimental observations. We argue that previously reported some variations of physical properties (e.g., density, electrical conductivity, and magnetism) in bismuth could be due to the formation of these polytypes. The coexistence of metastable derivative structural polytypes may be a widely occurring phenomenon in other elemental materials.
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shu
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Wentao
authors.initials: W
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Zhongyuan
authors.initials: Z
authors.lastname: Liu
authors.affiliation: High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA.
authors.forename: Guoyin
authors.initials: G
authors.lastname: Shen
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Zhisheng
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Julong
authors.initials: J
authors.lastname: He
authors.affiliation: Center for Advanced Radiation Sources, University of Chicago, Argonne, Illinois 60439, USA.
authors.forename: Yanbin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Tian
authors.affiliation: State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao, Hebei 066004, China.
authors.forename: Dongli
authors.initials: D
authors.lastname: Yu