A general phase-field model for grain-boundary grooving and the agglomeration of polycrystalline alloy thin films was presented. In particular, the effects of slow-diffusing species on the grooving rate was studied. As the groove grew, the slow species became concentrated near to the groove-tip so that further grooving was limited by the rate at which it diffused away from the tip. In the early stages, the predominant diffusion path was along the boundary whereas, at later times, it was parallel to the substrate. This change in path strongly affected the time-dependence of grain-boundary grooving and increased the time to agglomeration. The model provided a tool for agglomeration-resistant thin-film alloy design.

Grain-Boundary Grooving and Agglomeration of Alloy Thin Films with a Slow-Diffusing Species. M.Bouville, D.Chi, D.J.Srolovitz: Physical Review Letters, 2007, 98[8], 085503 (4pp)