Core level binding energy shifts in dilute tin alloys

X‐ray photoelectron spectra of Cu 95 Sn 5 and In 95 Sn 5 alloys have been recorded using a VG Scientific ESCA‐3, MK II electron spectrometer. The binding energy of Sn 3d level in these alloys is compared with that in pure Sn(ß). From the above results, and also from those published earlier, it is clear that the binding energy shift depends on the electronegativity difference, the coordination number and also the interatomic distance. A simple empirical equation was arrived at to get the best fit with the experimental data. In general the agreement between the calculated and measured binding energy shifts is quite satisfactory.