title: Structural phase transitions in Bi2Se3 under high pressure.
abstract: Raman spectroscopy and angle dispersive X-ray diffraction (XRD) experiments of bismuth selenide (Bi2Se3) have been carried out to pressures of 35.6 and 81.2 GPa, respectively, to explore its pressure-induced phase transformation. The experiments indicate that a progressive structural evolution occurs from an ambient rhombohedra phase (Space group (SG): R-3m) to monoclinic phase (SG: C2/m) and eventually to a high pressure body-centered tetragonal phase (SG: I4/mmm). Evidenced by our XRD data up to 81.2 GPa, the Bi2Se3 crystallizes into body-centered tetragonal structures rather than the recently reported disordered body-centered cubic (BCC) phase. Furthermore, first principles theoretical calculations favor the viewpoint that the I4/mmm phase Bi2Se3 can be stabilized under high pressure (>30 GPa). Remarkably, the Raman spectra of Bi2Se3 from this work (two independent runs) are still Raman active up to ~35 GPa. It is worthy to note that the disordered BCC phase at 27.8 GPa is not observed here. The remarkable difference in atomic radii of Bi and Se in Bi2Se3 may explain why Bi2Se3 shows different structural behavior than isocompounds Bi2Te3 and Sb2Te3.
authors.affiliation: Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, People's Republic of China.
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, People's Republic of China.|State Key Laboratory of Superhard Materials, Jilin University, Changchun 130012, People's Republic of China.|Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States of America.
authors.forename: Lin
authors.initials: L
authors.lastname: Wang
authors.affiliation: Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, People's Republic of China.|Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States of America.
authors.forename: Qingyang
authors.initials: Q
authors.lastname: Hu
authors.affiliation: Natural Science Research Center, Academy of Fundamental and Interdisciplinary Sciences, Harbin Institute of Technology, Harbin 150080, People's Republic of China.
authors.forename: Jinggeng
authors.initials: J
authors.lastname: Zhao
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201203, People's Republic of China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Yan
authors.affiliation: Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201203, People's Republic of China.
authors.forename: Ke
authors.initials: K
authors.lastname: Yang
authors.affiliation: High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, United States of America.
authors.forename: Stanislav
authors.initials: S
authors.lastname: Sinogeikin
authors.affiliation: Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, New York 11973, United States of America.
authors.forename: Genda
authors.initials: G
authors.lastname: Gu
authors.affiliation: Center for High Pressure Science and Technology Advanced Research, Shanghai, 201203, People's Republic of China.|High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, United States of America.|Geophysical Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States of America.
authors.forename: Ho-kwang
authors.initials: HK
authors.lastname: Mao