A least-squares computational method was described for the fitting of experimental diffusion data to the Whipple-Suzuoka equations of grain-boundary diffusion. The basic equations were extended so as to include diffusion within the grain boundary, so that the method was applicable to Harrison type-B and/or type-C kinetics. The method involved no approximations or assumptions, apart from those of Whipple, and required the grain-boundary half-width, volume diffusivity and annealing time to be specified. The fitting parameters were the half-distance between parallel grain boundaries, and the ratio of the diffusivity in the grain boundary to that in the bulk.

A Least Squares Method for Fitting Diffusion Data to the Whipple/Suzuoka Equations for Grain Boundary Diffusion D.Shaw, T.L.Shaw: Journal of Applied Physics, 1998, 84[7], 3586-92