Resistivity, superconductivity, and order-disorder transformations in transition metal carbides and hydrogen-doped carbides
Electron transport in transition metal carbides was investigated, with special attention to ordering effects in substoichiometric specimens and to the influence of hydrogen doping. Hydrided carbides specimens showed reduced resistivity values, a result attributed to the reduction of defect scattering as the carbon vacancies were filled with substitutional hydrogen ions. The effect of the order-disorder transformation NbC/sub 0.83/ = Nb/sub 6/C/sub 5/ at 1030 /sup 0/C was also to reduce defect scattering as the carbon vacancies became incorporated into the periodic potential of the ordered phase. As another illustration of vacancy scattering, the resistivities of non-stoichiometric HFC/sub x/ and stiochiometric WC were compared. The superconducting transition temperatures of partially ordered Nb/sub 6/C/sub 5/ and hydrided NbC/sub x/ decreased from those of the original specimens, disordered NbC/sub 0.83/ and NbC/sub x/, respectively. The normal state resistivity of Nb/sub 6/C/sub 5/ displayed the bulge in its temperature dependence characteristic of high T/sub c/ superconducters. New data on the normal state resistivity and superconducting transition of single crystal NbC/sub 0.98/ and TaC/sub 0.98/ are presented, and a theorectical relation linking normal state resistivity and superconductivity is developed.
- Research Organization:
- Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
- DOE Contract Number:
- AC02-76ER01198
- OSTI ID:
- 6617625
- Journal Information:
- J. Appl. Phys.; (United States), Journal Name: J. Appl. Phys.; (United States) Vol. 53:12; ISSN JAPIA
- Country of Publication:
- United States
- Language:
- English
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75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BINDING ENERGY
CARBIDES
CARBON COMPOUNDS
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
CRYSTALS
DATA
DEUTERIDES
DEUTERIUM COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ENERGY
EXPERIMENTAL DATA
HYDROGEN ADDITIONS
HYDROGEN COMPOUNDS
INFORMATION
MEDIUM TEMPERATURE
MONOCRYSTALS
NIOBIUM CARBIDES
NIOBIUM COMPOUNDS
NUMERICAL DATA
ORDER-DISORDER TRANSFORMATIONS
PHASE TRANSFORMATIONS
PHONONS
PHYSICAL PROPERTIES
POINT DEFECTS
QUASI PARTICLES
STOICHIOMETRY
SUPERCONDUCTIVITY
TANTALUM CARBIDES
TANTALUM COMPOUNDS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
TUNGSTEN CARBIDES
TUNGSTEN COMPOUNDS
ULTRALOW TEMPERATURE
VACANCIES
VANADIUM CARBIDES
VANADIUM COMPOUNDS