Theelectrical dislocation resistivity and the deviation fromMatthiessen's rule of deformed high-purity aluminium

Abstract

The experimental dislocation resistivity of rolled samples of99.9999% pure aluminium was investigated in the temperature rangefrom 4.2 K to 300 K. The minimum in the deviation from Matthiessen'srule (DMR) below 40 K and the step height of the DMR from 4.2 K to300 K can be explained by anisotropic scattering in terms of athree-group or a two-group model. The physical relevance of thefitted anisotropy parameters for electron-dislocation (Ad)and electron-phonon scattering (Ap) can be better seen inthe two-group model. The variation of Ad and Apwith dislocation density is similar to that for the noble metals,whereby Ap at low temperatures is much more anisotropic foraluminium. The change of Ap with increasing dislocationdensity for T⩽50 K can be understood if anisotropic small-anglescattering at local phonon modes originating from the dislocationsis taken into account. This anisotropy could arise, as the Burgersvectors of the dislocations are oriented mainly in [011] directions.