Vaporization of Solids: Evidence for a Zipper Mechanism in the Retarded Vaporization of Arsenic

Abstract

Recent observations indicate that the rate of evaporation of elemental arsenic into a vacuum is determined by the rate of formation, at screw dislocations, of kinks in ledges of molecular height. Once formed, a kink advances along the ledge, which makes a continuous spiral ramp outward from the dislocation, until the ledge terminates. A kink advances by releasing As₄ molecules from the ledge. A given kink releases almost 10⁶ As₄ molecules before the next kink is initiated.