Dislocations and the de Haas-van Alphen Effect in Copper

Experiments have been carried out to determine the effect of lattice dislocations in pure copper single crystals on the de Haas-van Alphen (dHv A) scattering (Dingle) temperature X. The measurements were made on copper samples of measured dislocation density under stringent experimental conditions, including a magnetic field homogeneity of better than 2 ppm and an orientation of the sample symmetry direction along the field to within 0.05^∘{}. The results for the [111] neck and belly orbits in copper showed a linear dependence of X on the dislocation density D over the range D0.5×10⁷ to 7×10⁷ cm^-2, with slopes given by XₙD0.32×10^-7 K cm² and XbD0.08×10^-7 K cm². Two approaches have been suggested to explain the results: (i) The scattering temperature is inversely proportional to the electron relaxation time and is therefore a direct measure of electron scattering from dislocations; (ii) X is due to phase cancellation in the dHv A signal from orbits moving within the spatially varying elastic strain field of the dislocation array. The experimental results are discussed in terms of these two points of view.