In this work, the interdiffusion coefficient and atomic mobility for fcc
Ag-Cu-Mg phase at 1073 K have been investigated by combining diffusion
couple experiments and calculations. Based on the experimental composition
profiles, the diffusion coefficients at intersection points in diffusion
paths were calculated by means of Matano-Kirkaldy method. Using the
thermodynamic descriptions available in literature, the atomic mobilities
for fcc Ag-Cu-Mg phase were automatically optimized by numerical inverse
method incorporated in the CALTPP (CALculation of ThermoPhysical Properties)
program. Moreover, the obtained atomic mobilities were verified to be
reliable through good agreements between the model-simulated composition
profiles and the measured ones. In addition, three-dimensional surfaces for
the interdiffusion coefficient, activation energy, and frequency factor were
presented. The presently obtained atomic mobilities can be incorporated into
the diffusion database for Ag-based alloys, which can contribute to
microstructure simulation and materials design.