Electron-Phonon Effects In Copper .1. Electron-Scattering Rate And Mass Enhancement

Phonon-limited quasiparticle-mass enhancement ${\ensuremath{\lambda}}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}$ and low-temperature lifetimes $\frac{1}{{\ensuremath{\tau}}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}}={c}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}{T}^{3}$ are calculated for Cu. Experimental phonons, Korringa-Kohn-Rostocker wave functions and the rigid-muffin-tin (RMT) model have been used. The results are compared with calculations of other groups and with experiment. It is found that the experiment of Doezema and Koch (DK) was not performed at a low enough temperature ($T$) to give the correct limiting value of ${c}_{\stackrel{\ensuremath{\rightarrow}}{\mathrm{k}}}$. The results at higher $T$ match well the data of DK and the calculation of Schmidt and Mann, but do not agree closely with the calculations of Nowak and Das. In contradiction to an earlier suggestion, the RMT model seems to work well at small momentum transfers.