Heat-capacity analysis of a large number of A15-type compounds

Journal Article · Tue Feb 01 04:00:00 EST 1983 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.27.1568· OSTI ID:6265120

Junod, A; Jarlborg, T; Muller, J

We analyze the low- and medium-temperature specific heat of 25 samples based on eleven A15 binary compounds, with T/sub c/'s ranging from less than 0.015 to 18 K. Experimentally determined ''moments'' of the phonon spectra (omega-bar,omega-bar/sub 2/,..omega../sub log/) are included in the analysis. Values are tabulated for T-bar/sub c/, /sup 2/, eta, , N/sub bs/(E/sub F/), Momega-bar/sub 2//sup 2/, H/sub c/(0), and 2..delta..(0)/k/sub B/T/sub c/. We note the following: (i) The Debye temperature is generally a bad estimate of ..omega../sub log/. (ii) lambda is governed mainly by the ''electronic parameter'' eta; lambda = 0.175eta(eV/A/sup 2/) +- 0.2 for all A15 compounds studied. (iii) eta is proportional to the density of states at the Fermi level and this density of states agrees well with band-structure calculations of Jarlborg in Nb-based compounds. In V-based compounds, the observed bad correlation may reflect the presence of spin fluctuations. (iv) The values for the reduced gap 2..delta..(0)/k/sub B/T/sub c/ range from 3.4 to 4.9 and they are correlated with T/sub c//..omega../sub log/.

• Research Organization: Departement de Physique de la Matiere Condensee, Universite de Geneve, CH-1211 Geneve 4, Switzerland
• OSTI ID: 6265120
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 27:3; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
656102 -- Solid State Physics-- Superconductivity-- Acoustic
Electronic
Magnetic
Optical
& Thermal Phenomena-- (-1987)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ALLOY SYSTEMS
ALLOYS
BETA-W LATTICES
BINARY ALLOY SYSTEMS
CRITICAL FIELD
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DEBYE TEMPERATURE
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELECTRONIC SPECIFIC HEAT
ENERGY GAP
EXPERIMENTAL DATA
INFORMATION
LOW TEMPERATURE
MAGNETIC FIELDS
NIOBIUM ALLOYS
NIOBIUM BASE ALLOYS
NUMERICAL DATA
PHONONS
PHYSICAL PROPERTIES
QUASI PARTICLES
SPECIFIC HEAT
SPECTRA
SUPERCONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION TEMPERATURE
ULTRALOW TEMPERATURE
VANADIUM ALLOYS
VANADIUM BASE ALLOYS
VERY LOW TEMPERATURE