title: High pressure Raman study of bromine and iodine: soft phonon in the incommensurate phase.
abstract: A new phase of solid bromine was discovered at a pressure region above 80 GPa by Raman scattering experiments with a diamond anvil high-pressure cell. This phase was found to be the same as the iodine phase V with an incommensurate structure [Nature (London) 423, 971 (2003)] which appears between the molecular phase I and the monatomic phase II. In the incommensurate phases of both bromine and iodine, Raman active soft modes were clearly found in the low frequency region. The data suggest that the monoatomic phase II occurs above 30 and 115 GPa for iodine and bromine, respectively.
authors.affiliation: Department of Materials Science and Technology, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu, 501-1193, Japan. kume@cc.gifu-u.ac.jp
authors.forename: Tetsuji
authors.initials: T
authors.lastname: Kume
authors.forename: Takashi
authors.initials: T
authors.lastname: Hiraoka
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Ohya
authors.forename: Shigeo
authors.initials: S
authors.lastname: Sasaki
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Shimizu