Calculated electrical and thermal resistivities of Nb and Pd

Journal Article · Fri May 15 04:00:00 EDT 1981 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.23.5080· OSTI ID:6343863

Pinski, F J; Allen, P B; Butler, W H

The electrical and thermal resistivities ( rho and W) of pure Nb and Pd are calculated from nearly first principles. Realistic Korringa-Kohn-Rostoker energy bands and wave functions, experimental phonon frequencies and Born--von Karman eigenvectors, and rigid muffin-tin electron-phonon potentials are used to generate the velocities and scattering probabilities in the Bloch-Boltzmann equation, at a mesh of nearly 48 000 points on the Fermi surface. Solutions for rho and W are exhibited at three levels of accuracy: (1) the lowest-order variational approximation (LOVA) where the Fermi surface displaces rigidly; (2) the N-sheet approximation where different sheets of Fermi surface displace independently; (3) a fully inelastic calculation where the N-sheet approximation is used and the distribution function is allowed arbitrary variations with energy (normal to the Fermi surface) to reflect the inelasticity of electron-phonon scattering. Above T = 100 K, corrections to LOVA are of order 1%, but below T = 100 K, both the N-sheet approximation and inelasticity give large corrections to the LOVA results. These results are also compared with Bloch-Grueneisen formulas fitted at Tapprox.THETA/sub D/. In the range 100 K< or approx. =T< or approx. =300 K, calculations exceed experimental results by approx.10%. Good agreement persists into the range 10 K< or approx. =T< or approx. =100 K, except that in Nb theory underestimates experiment significantly at the lower-temperature end, suggesting a possible error of rigid muffin-tin models for small Q scattering. In Pd the interpretation is complicated by Coulomb effects. Below T = 10 K, finite mesh size prevents reliable calculations. Simple models such as Bloch-Grueneisen theory are inadequate to account for the data. Mott's (1936) ''s-d'' picture is shown to be qualitatively correct for Pd. Extension of this picture to Nb was suggested subsequently by various authors, but the present calculation does not support this.

• Research Organization: State University of New York at Stony Brook, Stony Brook, New York 11794
• OSTI ID: 6343863
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 23:10; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals &amp; Alloys-- Physical Properties
DISTRIBUTION FUNCTIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY LEVELS
FERMI LEVEL
FUNCTIONS
METALS
NIOBIUM
PALLADIUM
PHYSICAL PROPERTIES
PLATINUM METALS
REFRACTORY METALS
THERMAL CONDUCTIVITY
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENTS
VARIATIONAL METHODS
WAVE FUNCTIONS