Critical Assessment of Microwave-Enhanced Diffusion

The use of microwave heating or microwave plasmas in the sintering of ceramics has often been observed to result in more rapid sintering than the same heating schedule in a conventional furnace; the increased sintering rate has sometimes been ascribed to the enhancement of diffusion by microwave heating/plasma. Some experiments on diffusion measurements under microwave heating have also been carried out in order to check this hypothesis. In this paper, we evaluate the experimental evidence for microwave enhanced diffusion, discuss the various models that have been proposed for the enhanced diffusion, and suggest some further experiments aimed at understanding these phenomena.