Ambipolar diffusion in sintering and diffusional creep of ionic compounds

Abstract

The effective diffusion coefficient (D) over bar during sintering or diffusional creep of a polycrystalline ionic (ceramic) compound MaXb has been reexamined and suggested to be (D) over bar = DMDX/ (bD(M) + aD(X)), where Di is the diffusion coefficient of ion i (=M, X), in agreement with some previous investigations. This expression should be applicable to any system where ambipolar diffusion is driven by a stress gradient.