Measurement of Conduction-Electron-Spin Relaxation in Sodium, 14-20 K

Conduction-electron-spin relaxation in sodium has been measured in the liquid-hydrogen-temperature range 14-20 K. We believe we have successfully separated the contributions to the measured relaxation rate from the impurity, surface, and electron-phonon (intrinsic) mechanisms by working with samples of controlled geometry at low rf frequency (10 MHz). The temperature dependence of the intrinsic relaxation time agrees reasonably well with the Debye-model calculations of Yafet. In our samples the probability of relaxation per surface collision for an electron spin is on the order of 10^-3.