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 (TD) 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 TD has local minima at 112̄0 directions in the basal plane and increases when the field direction is rotated from 112̄0 towards 0001. In the deformed crystal this anisotropy of TD is more pronounced. We disagree with Brown and Friedberg, who report that TD is independent of the field direction in the basal plane and decreases by a factor of 5 as the field direction is rotated from 112̄0 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.
ASJC Scopus subject areas
- Condensed Matter Physics