Smoothening of the non-Euclidean surface of Nd2O3 doped CeO2 nanoceramic grains under sintering: an ultra-small angle x-ray scattering investigation and a computer simulation study

Smoothing of the fractal rough surface of Nd2O3 doped CeO2 ceramic under sintering has been observed in an ultra-small angle x-ray scattering investigation. The surface fractal dimension of 2.6 for the non-sintered specimen reduces with sintering temperature and gradually attains a value of 2.0, which corresponds to a smooth surface, at a high enough sintering temperature. A Monte Carlo based computer simulation has been attempted to explain the smoothing of such a fractally rough surface due to the diffusion based surface transport of the materials from a region of positive curvature to one of negative curvature. The variation of the interface width and the evolution of the fractal dimension with sintering have been estimated from this model simulation