An Initial Stage Model for the Sintering of Constrained Polycrystalline Thin Films

A physical model has been developed for the initial stage of sintering of thin constrained polycrystalline films. The model compares the shrinkage of constrained thin films to the shrinkage of unconstrained or free sintering material. It predicts that the volumetric shrinkage of a constrained thin film will be slightly more than the linear shrinkage for the free sintering case, but far less than the volumetric shrinkage for the free sintering case. Model predictions show that the sintering of a constrained film is highly dependent on the ratio of the boundary energy to the surface energy, and on grain growth. The model was used to fit the experimental data of Garino & Bowen, for the sintering of constrained alumina and zinc oxide films