The Frank—Read source

Abstract

Frank first became interested in dislocations through reading Taylor’s 1934 paper. He wrote to Taylor, pointing out that his model was two-dimensional, and asking if a dislocation had to be a straight line. This letter was not answered, and Frank did not think further about dislocations until he came to Bristol at Mott’s invitation after the war, when he read the paper by J. M. Burgers early in 1947 and realized that the question was answered, and that one should think in three dimensions instead of two. Mott asked him to give a series of seminars on nucleation and crystal growth, and he then realized that the predicted rate of growth was 10 1000 times too small, and - the key point - that if a screw dislocation emerged from a crystal face, nucleation was unnecessary. The ‘spiral’ theory of Burton, Cabrera & Frank followed. There was a summer school in Bristol at which Frank explained the theory, and Griffin, from Tolansky’s laboratory, in the audience, produced photographs showing not only spirals, but other more complex features predicted by the theory (see Griffin 1951).