Study of pressure effect on superconductivity in C-15 laves phase alloys: (Hf, Zr, Ta)V/sub 2/ and (Hf, Zr, Nb)V/sub 2/ system

Journal Article · Sat Jan 01 04:00:00 EST 1983 · Chin. Phys.; (United States)

OSTI ID:6264994

Xiong, G C; Yin, D L

The superconducting transition temperatures T/sub c/ and its pressure dependence partialT/sub c//partialP on some C-15 laves phase compounds, (Zr/sub 0.5/Hf/sub 0.5-x/Ta/sub x/)V/sub 2/ (x< or =0.2) and (Hf/sub 0.5/Zr/sub 0.5-x/Nb/sub x/)V/sub 2/ (x< or =0.2) system, have been studied. A description of the experimental apparatus and results is given. Unlike the cases of (Hf/sub 1-x/Ta/sub x/)V/sub 2/ and (Zr/sub 1-x/Ta/sub x/)V/sub 2/ , introduction of Ta in (Zr/sub 0.5/Hf/sub 0.5-x/Ta/sub x/)V/sub 2/ depresses T/sub c/ under normal pressure but causes a remarkably higher partialT/sub c//partialP. The superconducting transition temperature T/sub c/ of (Zr/sub 0.5/Hf/sub 0.45/Ta/sub 0.05/)V/sub 2/ is higher than that of (Zr/sub 0.5/Hf/sub 0.5/)V/sub 2/ at high pressure. Based on the band theory method with angular momentum representation, a new relation for the pressure dependence of electron-phonon coupling (i.e., partial ln eta/partial ln V) is derived. It emphasizes the relative importance of the effect on high angular-momentum components in the conduction band electron wave function of 2 ln eta/2 ln V. This formulation is helpful in understanding the above-mentioned experimental results and also gives a reasonable explanation of the fact that T/sub c/ of some elements, e.g., Cs, Ba, and La, is substantially enhanced by pressure.

• Research Organization: Department of Physics, Peking University
• OSTI ID: 6264994
• Journal Information: Chin. Phys.; (United States), Journal Name: Chin. Phys.; (United States) Vol. 3:1; ISSN CHPHD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals &amp; Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
&amp; Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOYS
BAND THEORY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRON-PHONON COUPLING
ELEMENTS
HAFNIUM ALLOYS
LAVES PHASES
METALS
NIOBIUM ALLOYS
PHYSICAL PROPERTIES
PRESSURE DEPENDENCE
SUPERCONDUCTIVITY
TANTALUM
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
TRANSITION TEMPERATURE
VANADIUM ALLOYS
VANADIUM BASE ALLOYS
ZIRCONIUM ALLOYS