Published in Physical Review B, Volume 33, Issue 3, February 1, 1986, pages 1634-1640.
Copyright © 1986 American Physical Society. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Physical Society. The following article appeared in Physical Review B.
NOTE: At the time of publication, the author Matthew Moelter was not yet affiliated with Cal Poly.
The definitive version is available at http://dx.doi.org/10.1103/PhysRevB.33.1634.
The plastic deformation of bcc 3He crystals has been studied near the melting curve, in the temperature range 0.65 K ≤T≤.17 K, and for strain rates, ɛ˙, from 2x10-6 to 2x10-4 sec-1. The resulting relations between strain rate and stress, at a given temperature, are accounted for in terms of dislocation climb and vacancy diffusion in the solid He. The temperature dependence of the strain rate at a given stress indicates that a nonclassical mechanism underlies the deformation process. The vacancy diffusion coefficient in bcc 3He, as a function of temperature, is deduced from these results, and an energy bandwidth for delocalized vacancies of 0.24±0.05 K is obtained through a fit to theoretical predictions.