A model of whisker crystal growth from a pentagonal small particle

We present a physical model of growth of whisker crystals from metal pentagonal small particles (PSPs). The model is based upon the notions of nucleation and slippage of prismatic dislocation loops in the elastic field of disclination defects that are inherent in PSPs. In the framework of this model, the escape of interstitial dislocation loops at the PSP surface leads to an increase in the whisker length relative to the base, while incorporation of the vacancy-type loops is accompanied by their accumulation on the internal surface. The model is illustrated by calculations that show a gain in the total PSP energy as a result of the formation of a pair of prismatic dislocation loops with opposite signs.