Determination of Relaxation Times in Cyclotron Resonance in Copper

Azbel'-Kaner cyclotron resonance has been used to determine the effective electron relaxation time on the Fermi surface of copper. The temperature-dependent part of the cyclotron-resonance relaxation time is found to have a $T^m$ temperature dependence where $m=3.05\mathrm{}\pm 0.14$ for the belly electrons and $m=3.1\mathrm{}\pm 0.9$ for the neck electrons. The anisotropy in the temperature-dependent relaxation time as given by $\frac{{\tau }_B}{{\tau }_N}$, the ratio of the belly relaxation time to the neck relaxation time, is found to have the value $\frac{{\tau }_B}{{\tau }_N}=10\mathrm{}$ within a factor of 2.