Theoretical and experimental estimates of the Peierls stress

Abstract

Abstract The Peierls stress is the stress required to move a dislocation through a perfect crystal lattice. Theoretical estimates show an exponential dependence on the ratio of the spacing between gliding planes and the unit slip distance. Nabarro corrected an error of a factor of 2 in this exponent in Peierls's original estimate. A revised estimate by Huntington introduced a further factor of 2. Three experimental estimates are available, from the Bordoni peaks (which agrees with the Huntington theory), from the flow stress at low temperatures (which agrees with the P—N (Peierls—Nabarro) theory) and from the rate of Harper—Dorn creep (which agrees with the P—N theory). Since the Huntington theory is clearly better founded than that of P—N, the agreement of two experimental results with P—N is unexpected. The discrepancy is resolved by using a recent result by Schoeck.