The Raman spectrum of icosahedral alpha-boron presents a very sharp peak at 525cm(-1) that was consistently rejected from the lattice modes but is still unexplained. New Raman scattering experiments under pressure are compared with ab-initio lattice dynamics calculations. The very good agreement of the mode frequencies and their pressure coefficients yields unambiguous assignment of all observed features, including the 525 cm(-1) line which is a highly harmonic librational mode of the icosahedron. This mode is also identified in the Raman spectrum of other icosahedral boron-rich solids.
|Titolo:||Lattice dynamics of alpha-boron from ab-initio calculation and Raman scattering under high pressure|
|Autori:||Vast N; Baroni S; Zerah G; Besson JM; Polian A; Grimsditch M; Chervin JC|
|Rivista:||PHYSICA STATUS SOLIDI B-BASIC RESEARCH|
|Data di pubblicazione:||1996|
|Digital Object Identifier (DOI):||10.1002/pssb.2221980116|
|Appare nelle tipologie:||1.1 Journal article|