PEIERLS-BARRIER THEORY.

The research accomplishments of a two year study of the Peierls-barrier are reported. Metals deform plastically principally by movement of dislocations and the Peierls-barrier is one of the impediments to such motion. Earlier work had indicated that the Peierls-barrier depends mainly on three parameters. The present work shows that these reduce to two parameters which are so closely related as to constitute a single complex parameter, a complex width where the real part is ordinary width and the imaginary part is the separation of partials if the dislocation is dissociated. Author