The kinetics of Rh diffusion were studied on a sharp Rh/Pt(110) interface which had been created via the molecular beam epitaxial evaporation of 0.5 or 1 monolayer of Rh onto a reconstructed (110)Pt 1 x 2 substrate. It was found that the barrier height for Rh diffusing into Pt was equal to 2.69eV. Various equilibrium structural phases, c(2 x 2), 1 x 3, and 1 x 2, were observed by means of low-energy electron diffraction. They were associated with certain Rh concentrations. Excess surface segregation of Pt occurred at temperatures above 870K. This temperature was about 70K higher than the onset temperature in bulk Pt-Rh alloy.

Y.L.He, J.K.Zuo, G.C.Wang, J.J.Low: Surface Science, 1991, 255[3], 269-79