Crystal structure and lattice dynamics of ThC/sub 0. 063/

Journal Article · Thu May 15 00:00:00 EDT 1980 · Phys. Rev., B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.21.4500· OSTI ID:5441506

Kamitakahara, W A; Khatamian, D; Peterson, D T; Mook, H A

Neutron scattering methods have been used to investigate the structure and dynamics of single crystals of thorium containing 6 at. % interstitial carbon. Diffraction data show unambiguously that the carbon atoms occupy octahedral sites in the fcc thorium lattice. Inelastic scattering measurements reveal that the acoustic-phonon dispersion curves of ThC/sub 0.063/ differ very little from those of pure Th, despite the strong binding of C in Th, thus indirectly indicating that C addition weakens the metal-metal force constants. The local-mode vibrations of the C atoms were observed as a strong sharp peak in the inelastic scattering at an energy of 10.6 THz, with little or no indication of broadening due to dispersion or disorder. The high frequency of the carbon vibration and lack of broadening imply strong C-Th near-neighbor force constants, and that more-distant C-C interactions are weak.

• Research Organization: Ames Laboratory, U.S. Department of Energy and Departments of Physics and Materials, Science and Engineering, Iowa State University, Ames, Iowa 50011
• OSTI ID: 5441506
• Journal Information: Phys. Rev., B: Condens. Matter; (United States), Vol. 21:10
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
THORIUM CARBIDES
CRYSTAL STRUCTURE
LATTICE VIBRATIONS
NEUTRON DIFFRACTION
INTERSTITIALS
MONOCRYSTALS
PHONONS
SOLID SOLUTIONS
ACTINIDE COMPOUNDS
CARBIDES
CARBON COMPOUNDS
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTALS
DIFFRACTION
DISPERSIONS
MIXTURES
POINT DEFECTS
QUASI PARTICLES
SCATTERING
SOLUTIONS
THORIUM COMPOUNDS
360202* - Ceramics
Cermets
& Refractories- Structure & Phase Studies