Abnormal grain growth in thin films not caused by decreased energy of their free surface

We modeled the grain growth process in thin films on substrate. The only driving force for grain growth was a decrease in the total grain boundary energy; possible difference in the energies of the free surface of neighboring grains was not taken into account. The main features of capillarity-driven microstructure evolution qualitatively agree with those observed experimentally. This leads to the conclusion that abnormal grain growth in thin films can develop without assistance of decreased energy of the free film surface. (C) 2011 Elsevier B.V. All rights reserved.