Optical and electrical properties of niobium carbide

Journal Article · Sun Feb 15 04:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.35.2573· OSTI ID:6716359

Allison, C Y; Modine, F A; French, R H

The optical and electrical properties were measured for single crystals of NbC/sub x/ for x = 0.98, 0.87, and 0.76, and for one hot-isostatically-pressed sample of NbC/sub 0.88/. Specular reflectance was measured between 0.025 and 11 eV, and ellipsometry measurements were made at 1.96 eV. By using the phase obtained from ellipsometry data to correct the Kramers-Kronig analyses of the reflectances, we were able to improve the accuracy of the resulting optical functions. For energies below 6.5 eV, there are differences in the reflectance and optical functions of the samples which are due to differences in x. We interpret the low-energy optical data in terms of intraband transitions, which allows us to calculate the dc conductivity as well as other electronic transport parameters. These parameters agree well with the electrical conductivities and the Hall coefficients obtained by the van der Pauw technique. The higher-energy optical data are interpreted in light of recent electronic-structure calculations, which suggest that most interband transitions occur near the square face of the Brillouin zone.

• Research Organization: Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6716359
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 35:6; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
BRILLOUIN ZONES
CARBIDES
CARBON COMPOUNDS
CRYSTALS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
ELLIPSOMETRY
HALL EFFECT
MEASURING METHODS
MONOCRYSTALS
NIOBIUM CARBIDES
NIOBIUM COMPOUNDS
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SPECTRAL REFLECTANCE
TRANSITION ELEMENT COMPOUNDS
ZONES