Theoretical and experimental estimates of the Peierls stress

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 how 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.