Evaluating atomic mobility and interdiffusivity based on two-dimensional diffusion simulations and diffusion triple experiments

Abstract Diffusion triples or multiples are commonly considered as high-throughput experiments to study phase equilibrium and diffusion. But when extracting diffusion coefficients, they are treated as diffusion couples with one-dimensional (1D) composition variation, never taking advantage of their two-dimensional (2D) composition distributions. In this work, we present an efficient numerical inverse approach to directly evaluate composition-dependent atomic mobilities and full matrix of interdiffusivities based on a novel 2D diffusion simulation scheme, which was applied to the Co–Fe–Ni alloys by analyzing only one diffusion triple over a wide composition range. Its reliability was confirmed by comparing with traditional methods.