Effect of annealing on the temperature dependence of the electrical resistivity of aluminium

The temperature dependence of the electrical resistivity of four samples of aluminium has been measured over the range 1.2-4.2K. The samples were annealed at successively higher temperatures between measurements. It has been found that upon annealing the samples, the electron-phonon scattering term increased by about 60% whereas the electron-electron scattering term decreased by about 20-30%. The effect of the successive annealings has been to reduce the dislocation density in the samples. A theoretical analysis has been presented, based on the idea that a reduced dislocation density tended to give an isotropic electron relaxation time. A calculation has been carried out which yields agreement between theory and experiment for both the increase in the electron-phonon scattering term and the decrease in the electron-electron scattering term.