BJ Kim, RE García, EA Stach “Kinetics of Congruent Vaporization of ZnO Islands.” Physical Review Letters. 107(14):146101, 2011.

Abstract

We examine the congruent vaporization of ZnO islands using in situ transmission electron microscopy. Correlating quantitative measurements with a theoretical model offers a comprehensive understanding of the equilibrium conditions of the system, including equilibrium vapor pressure and surface free energy. Interestingly, the surface energy depends on temperature, presumably due to a charged surface at our specific condition of low $P$ and high $T$. We find that the vaporization temperature decreases with decreasing system size, a trend that is more pronounced at higher $T$. Applying our results of island decay towards the growth of the ZnO provides new insights into the cooperative facet growth of anisotropic nanocrystals.