dHvA measurements of long range strain effects due to lattice dislocations in copper

Abstract

Lattice dislocations have been shown to produce a factor of 10³ greater dHvA scattering temperature than an estimate from resistivity. The magnitude of this discrepancy is explained by a first principles phase smearing calculation, and is due to the sensitivity of the quantum oscillations to small angle scattering by the long range strain field. Breaking the cubic symmetry by introducing a forest of edge dislocations allows a test of the sensitivity of previously equivalent neck orbits to the relative orientation with respect to the dislocation lines. Both magnitudes and anisotropy agree with the theory. It is shown how to separate these effects from mosaic structure effects also present in these deformed crystals. In a separate experiment, neutron irradiation was used to produce dislocation loops. Here, the dHvA scattering is observed to be of the same order as resistivity scattering, due to the cancellation of the long range dislocation strain field in the loop geometry.