Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Anisotropic quasiparticle properties in aluminum

Technical Report ·
DOI:https://doi.org/10.2172/7251839· OSTI ID:7251839

The electron-phonon interaction in aluminum was studied using Fermi-surface-fitted 4-OPW electron states, a realistic phonon spectrum, and integration mesh-density varying with local Fermi surface curvature. The resulting electron mass enhancement lambda and thermal scattering rate tau/sup -1/ are evaluated as functions of position on the Fermi surface. It was found that the agreement between observed and calculated cyclotron masses is improved by the use of an anisotropic effective mass enhancement (lambda) rather than the average one. The anisotropy of lambda is determined predominantly by mixing coefficient variations, rather than by phonon anisotropy. The scattering rate tau/sup -1/ exhibits order-of-magnitude variations over the Fermi surface at low temperatures. Its values at 5/sup 0/K are within 50% of the experimentally observed ones everywhere, with better agreement in free-electron regions. In free-electron regions, umklapp processes cause a more rapid increase than T/sup 3/ for temperatures above 15 to 25/sup 0/K. On ridges, where the initial T/sup 3/-coefficient is very large, a slower increase is found. There results a washingout of anisotropy with increasing temperature. The results on lambda are in good agreement with those of a recent similar calculation; the tau/sup -1/ results agree qualitatively but not quantitatively.

Research Organization:
Dartmouth Coll., Hanover, N.H. (USA). Dept. of Physics
DOE Contract Number:
EY-76-S-02-2315
OSTI ID:
7251839
Report Number(s):
COO-2315-8
Country of Publication:
United States
Language:
English