Sintering of ZnO: I, Densification and Grain Growth*

Densification and grain growth rates at the intermediate stage of the sintering of pressed zinc oxide pellets were measured in air and oxygen. Application of a lattice diffusion model to the results gave calculated diffusion coefficients in good agreement with directly measured diffusion coefficients for zinc. The change of atmosphere from air to oxygen resulted in lowering of grain size and calculated diffusivity; the diffusion decrease is consistent with lattice diffusivity of zinc occurring by an interstitial mechanism. The results can be expressed by the relations: image in air, and image in oxygen, from 900° to 100°C.