We have studied the effect of intrinsic defects, such as dislocations and mosaic structures, on the de Haas–van Alphen amplitudes in magnesium crystals. The Dingle temperature ($T_D$) of the monster orbit has been measured as a function of the magnetic field direction in as-grown and deformed pure crystals as well as in alloyed crystals. In the as-grown pure and alloyed crystals $T_D$ has local minima at 〈112¯0〉 directions in the basal plane and increases when the field direction is rotated from 〈112¯0〉 towards 〈0001〉. In the deformed crystal this anisotropy of $T_D$ is more pronounced. We disagree with Brown and Friedberg, who report that $T_D$ is independent of the field direction in the basal plane and decreases by a factor of 5 as the field direction is rotated from 〈112¯0〉 towards the 〈0001〉 direction. Our present results can be easily explained in terms of dephasing caused by dislocations as well as by mosaic structures of the crystal and are consistent with the results of Chang and Higgins obtained in deformed copper cyrstals.

• Received 24 September 1985

DOI:https://doi.org/10.1103/PhysRevB.33.2809