Structure of icosahedral borides by Raman spectroscopy

Conference · Mon Jul 01 00:00:00 EDT 1991 · AIP Conference Proceedings (American Institute of Physics); (United States)

DOI:https://doi.org/10.1063/1.40841· OSTI ID:7202442

Tallant, D R; Aselage, T L; Emin, D ^[1]

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1. Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

We have obtained Raman spectra of icosahedral boron-rich solids. The spectra of {alpha}-rhombohedral boron, boron arsenide, and boron phosphide are consistent with highly-ordered materials. Polarization studies have resulted in symmetry assignments for most of the Raman bands of {alpha}-rhombohedral boron. In contrast, the Raman spectra of the boron carbides reveal local substitutional disorder. They also change progressively as a function of carbon content. A structural model for the boron carbides has been developed to explain the Raman and infrared absorption spectra, x-ray data, and electrical and thermal transport properties. Raman spectra of boron carbide samples enriched in {sup 10}B, {sup 11}B, and {sup 13}C reveal details of the atomic motions. The vibrational frequencies and exceptionally narrow linewidths of certain Raman modes are discussed in terms of a strong'' bond model. In this model certain vibrational modes involving relatively stiff bonds between chain atoms, chain and icosahedral atoms, and atoms on different icosahedra are decoupled from the boride lattice by weak, intraicosahedral bonds.

• DOE Contract Number: AC04-76DP00789
• OSTI ID: 7202442
• Report Number(s): CONF-900870--
• Journal Information: AIP Conference Proceedings (American Institute of Physics); (United States), Journal Name: AIP Conference Proceedings (American Institute of Physics); (United States) Vol. 231:1; ISSN 0094-243X; ISSN APCPC
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
ARSENIC COMPOUNDS
ARSENIDES
BORON ARSENIDES
BORON CARBIDES
BORON COMPOUNDS
CARBIDES
CARBON COMPOUNDS
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
INFRARED SPECTRA
LASER SPECTROSCOPY
LATTICE VIBRATIONS
PHYSICAL PROPERTIES
PNICTIDES
POLARIZATION
RAMAN SPECTROSCOPY
SPECTRA
SPECTROSCOPY
TEMPERATURE EFFECTS
X-RAY SPECTRA