Abstract
We have studied the electron-phonon interaction in aluminum using Fermi-surface-fitted 4-orthogonalized-plane-wave electron states, a realistic phonon spectrum, and integration mesh density varying with local Fermi-surface curvature. The resulting electron-mass enhancement and thermal scattering rate are evaluated as functions of position on the Fermi surface, with the following results: (i) The agreement between observed and calculated cyclotron masses is improved slightly by the use of our anisotropic rather than the average one. (ii) The anisotropy of is determined predominantly by mixing coefficient variations, rather than by phonon anisotropy. (iii) The scattering rate exhibits order-of-magnitude variations over the Fermi surface at low temperatures. Its values at 5 K are within 50% of the experimentally observed ones everywhere, with considerably better agreement in free-electron regions. (iv) Deviations from the naively expected behavior are predicted: In free-electron regions, umklapp processes cause a more rapid increase than for temperatures above 15-25 K. On ridges, where the initial " coefficient" is very large, we find a slower increase. There results a washing out of anisotropy with increasing temperature. The results on are in good agreement with those of a recent similar calculation; the results agree qualitatively but not quantitatively.
- Received 12 October 1976
DOI:https://doi.org/10.1103/PhysRevB.15.1850
©1977 American Physical Society