Diffusivity Measured by X-ray Diffraction

Abstract

The advancement of x-ray diffraction theory and techniques, combined with established diffusion models, enables the rate controlling parameter(s) of a transformation or reaction process to be conveniently measured in an in-situ manner. This article briefly describes the technique employed for kinetics measurements and analytical procedures required for data interpretation. Two approaches are adopted to extract the interdiffusion coefficient from the kinetics data—the direct space approach and the reciprocal space approach. Three examples are presented to demonstrate the usefulness of this analysis: the growth kinetics of a Pd₂Si layer on Si, the decomposition kinetics of a supersaturated Ni-Si alloy, and the short range ordering of a nonrandom solid solution.