Electronic structure investigated by NMR and superconductivity of cubic Laves-phase hydrides: V/sub 2/HfH/sub x/ (0less than or equal toxless than or equal to4. 5) and V/sub 2/Hf/sub 0. 5/Zr/sub 0. 5/H/sub x/

Journal Article · Thu Sep 01 04:00:00 EDT 1988 · Phys. Rev. B: Condens. Matter; (United States)

OSTI ID:7090210

Daeumer, W; Khan, H R; Lueders, K

The /sup 51/V Knight shift and spin-lattice relaxation time were measured as a function of hydrogen concentration and temperature in the Laves-phase (C15) hydrides V/sub 2/HfH/sub x/ and V/sub 2/Hf/sub 0.5/Zr/sub 0.5/H/sub x/. In addition, the lattice parameters and the superconducting transition temperatures T/sub c/ were determined. An NMR line splitting was found at xgreater than or equal to1.1 obviously caused by different distributions of the H atoms on certain interstitial sites. A maximum in (T/sub 1/T)/sup -1/ was observed for all hydrogenated samples between 140 and 300 K and used to determine the correlation time for the H diffusion and the value of the dynamic electric field gradient. Together with susceptibility data, the NMR results of V/sub 2/Hf/sub 0.5/Zr/sub 0.5/H/sub x/ were used to develop a phase diagram and to separate the s, d, and the orbital components of K, R, and chi and the s- and d-electron density of states. T/sub c/ decreases steadily up to x = 1 for V/sub 2/Hf/sub 0.5/Zr/sub 0.5/H/sub x/ and followed by a sharp drop, between x = 1.4 and x = 4.5 with no superconducting transition down to 20 mK. But for V/sub 2/Hf/sub 0.5/Zr/sub 0.5/H/sub 4.8/ a superconducting transition at 57 mK was observed.

• Research Organization: Fachbereich Physik, Freie Universitaet Berlin, D-1000 Berlin 33, Federal Republic of Germany
• OSTI ID: 7090210
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 38:7; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
656100 -- Condensed Matter Physics-- Superconductivity
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CRYSTAL LATTICES
CRYSTAL STRUCTURE
CUBIC LATTICES
DIAGRAMS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
HAFNIUM COMPOUNDS
HAFNIUM HYDRIDES
HYDRIDES
HYDROGEN COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOTOPES
KNIGHT SHIFT
LATTICE PARAMETERS
LAVES PHASES
LOW TEMPERATURE
MAGNETIC RESONANCE
MEDIUM TEMPERATURE
NUCLEAR MAGNETIC RESONANCE
NUCLEI
ODD-EVEN NUCLEI
PHASE DIAGRAMS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
RELAXATION
RESONANCE
SPIN-LATTICE RELAXATION
STABLE ISOTOPES
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VANADIUM 51
VANADIUM COMPOUNDS
VANADIUM HYDRIDES
VANADIUM ISOTOPES
ZIRCONIUM COMPOUNDS
ZIRCONIUM HYDRIDES