A Study of Diffusion by High‐temperature Electron Probe Microanalysis

Abstract The diffusion between a thin layer and an underlying substrate, with the formation of an intermetallic phase, was studied by electron probe microanalysis (EPMA) measurements with a simultaneous heating of the sample (High‐temperature EPMA ≡ HT‐EPMA). A thin‐film EPMA model calculating the thicknesses and compositions of two thin layers on a substrate (WALDO) was used. A new method with some necessary assumptions has been developed for determining the phase growth coefficients of intermetallic phases from HT‐EPMA measurements by iteratively comparing the measured and calculated X‐ray intensities. Results from the binary system of CuSn are in good agreement with others achieved by different methods reported in the literature. Differences in the case of the binary system of CuIn are discussed.