Superconductivity of the hydrides and deuterides of HfV/sub 2/
Current interest in the superconductivity of metal hydrides and deuterides has encouraged an investigation of the influence of hydrogen and deuterium absorption on the crystallographic and superconducting properties of the C15 (MgCu/sub 2/-type) intermetallic compound, HfV/sub 2/. Room temperature absorption of hydrogen (H) and deuterium (D) by HfV/sub 2/ at 2.5 x 10/sup 6/ Pa. was found to produce alloys of the compositions HfV/sub 2/H/sub 4/./sub 53/ +- 0.02 and HfV/sub 2/D/sub 4/./sub 55/ +- 0.02 which were stable upon removal to air. These fully hydrided and deuterated alloys were brought to equilibrium in various mixtures with HfV/sub 2/ to produce a range of alloy concentrations. Within the limits of measurement, the lattice parameters of the hydrides and deuterides of the same concentration were found to be identical, and the lattice expansion arising from absorption was found to vary linearly with hydrogen or deuterium concentration. These specimens, which were powdered by the absorption process, were tested for superconductivity to the compositions HfV/sub 2/H/sub 1/./sub 59/ and HfV/sub 2/D/sub 1/./sub 00/ by an inductance bridge method. Alloying with hydrogen was found to decrease T/sub c/ by 4.7/sup 0/K per mole of hydrogen per mole of HfV/sub 2/. The deuterides exhibit a more rapid decrease of T/sub c/ of 6.8/sup 0/K per mole deuterium. Upper critical field measurements of HfV/sub 2/D/sub 0/./sub 5/ indicate a depression of H/sub c2/ in comparison to HfV/sub 2/. These characteristics of the hydrides and deuterides are discussed on the basis of their lattice and electronic properties.
- Research Organization:
- Univ. of Pittsburgh
- OSTI ID:
- 7125043
- Journal Information:
- AIP (Am. Inst. Phys.) Conf. Proc.; (United States), Journal Name: AIP (Am. Inst. Phys.) Conf. Proc.; (United States) Vol. 34; ISSN APCPC
- Country of Publication:
- United States
- Language:
- English
Similar Records
Saturated hydrides in the HfV{sub 2}-D system
Investigation of a phase transition in HfV/sub 2/D/sub 4/
Related Subjects
360104 -- Metals & Alloys-- Physical Properties
360603* -- Materials-- Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
CRYSTAL STRUCTURE
DEUTERIDES
DEUTERIUM COMPOUNDS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
HAFNIUM ALLOYS
HAFNIUM COMPOUNDS
HYDRIDES
HYDROGEN COMPOUNDS
LATTICE PARAMETERS
PHYSICAL PROPERTIES
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VANADIUM ALLOYS
VANADIUM COMPOUNDS