Optical study of the stoichiometry-dependent electronic structure of TiC sub x , VC sub x , and NbC sub x

Journal Article · Sat Sep 15 04:00:00 EDT 1990 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.42.4979· OSTI ID:6338974

Koide, T; Shidara, T ^[1]; Fukutani, H ^[2]; Fujimori, A ^[3]; Miyahara, T; Kato, H ^[1]; Otani, S; Ishizawa, Y ^[4]

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1. Photon Factory, National Laboratory for High Energy Physics, Tsukuba, Ibaraki 305 (Japan)
2. Institute of Physics, Tsukuba University, Tsukuba, Ibaraki 305 (Japan)
3. Department of Physics, Faculty of Science, University of Tokyo, Tokyo 113 (Japan)
4. National Institute for Research in Inorganic Materials, Tsukuba, Ibaraki 305 (Japan)

The stoichiometry-dependent bulk electronic structure has been studied by optical spectroscopy for single crystals of TiC{sub {ital x}} with {ital x}=0.95 and 0.70, VC{sub {ital x}} with {ital x}=0.86 and 0.76, and NbC{sub {ital x}} with {ital x}=0.93, 0.84, and 0.71. The reflectance was measured in the energy range 0.5--40 eV for all of the samples and up to 100 eV for TiC{sub 0.95}, VC{sub 0.86}, and NbC{sub 0.93}. By correcting for the surface-roughness effect using the measured roughness values, the data were Kramers-Kronig analyzed to obtain the dielectric function and related functions. The observed interband transitions have been interpreted on the basis of existing calculations for the energy-band structure and partial density of states. The main peaks above 4 eV were assigned to transitions at and around the {ital X} and {ital Q} portions in the Brillouin zone. Their shifts to lower energy and reduced intensities with decreasing carbon concentration are discussed in terms of {ital p}-{ital d} hybridization. Features arising from transitions involving the initial or final states near the Fermi level were observed in the low-energy region.

• OSTI ID: 6338974
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 42:8; ISSN 0163-1829; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
BAND THEORY
CARBIDES
CARBON COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
ELECTRONIC STRUCTURE
ELEMENTS
EMISSION
EMISSION SPECTROSCOPY
METALS
NIOBIUM CARBIDES
NIOBIUM COMPOUNDS
PHOTOEMISSION
PHYSICAL PROPERTIES
POINT DEFECTS
REFRACTORY METAL COMPOUNDS
SECONDARY EMISSION
SPECTROSCOPY
STOICHIOMETRY
SUPERLATTICES
TITANIUM CARBIDES
TITANIUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VACANCIES
VANADIUM CARBIDES
VANADIUM COMPOUNDS