Peierls stress and kink pair energy in NaCl type crystals

Normalizing the critical resolved shear stress (CRSS) by the shear modulus G and the temperature by Gb3/kB (b: the strength of the Burgers vector) in the temperature dependence of CRSS vs. the temperature plots for {1 1 0}〈1 1 0〉 slip in eleven NaCl type crystals reported previously, it is found that there exist two groups of NaCl type crystals for {1 1 0}〈1 1 0〉 slip, i.e., the high Peierls stress group with the normalized Peierls stress of 0.0014 ± 0.0002 and the low Peierls stress group with the normalized Peierls stress of 0.0004 ± 0.0001. The origin of the presence of the two groups for {1 1 0}〈1 1 0〉 slip has been discussed based on the possible slight splitting of the dislocation core. On the other hand, the normalized CRSS vs. the temperature plots for {0 0 1}〈1 1 0〉 slip in seven NaCl type crystals fall in a single zone. Kink pair energies for the dislocations of the two slip systems have been estimated based on the line tension approximation from the estimated Peierls stress and also from the critical temperature at which the steep temperature dependence of the CRSS vanishes. The reported activation energies of the Bordoni peak in NaCl type crystals have been compared with the above estimated kink pair energies.