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.
Lattice dynamics of alpha-boron from ab-initio calculation and Raman scattering under high pressure / Vast, N.; Baroni, S.; Zerah, G.; Besson, J. M.; Polian, A.; Grimsditch, M.; Chervin, J. C.. - In: PHYSICA STATUS SOLIDI B-BASIC RESEARCH. - ISSN 0370-1972. - 198:1(1996), pp. 115-119. [10.1002/pssb.2221980116]
Lattice dynamics of alpha-boron from ab-initio calculation and Raman scattering under high pressure
Baroni, S.;
1996-01-01
Abstract
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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
