The comparative study of two dimensional condensation of Xe and Kr physisorbed on Ag(1 1 1) and Ag(1 0 0)

Adsorption isobars of Xe and Kr on Ag(1 1 1) and Ag(1 0 0) were observed simultaneously by an extremely-low-current low energy electron diffraction and an ellipsometry in the temperature range between 60 K and 90 K and in the equilibrium pressure range between 8 × 10−6 Pa and 2 × 10−4 Pa. Two dimensional condensation of the first layer of Xe on Ag(1 1 1) occurred at the temperature 0.3 ± 0.1 K higher than that on Ag(1 0 0). In the case of Kr on Ag(1 1 1) and Ag(1 0 0), the temperature difference was 0.2 ± 0.1 K. This temperature difference was discussed on the assumption that it is caused by the repulsive interaction between the dipoles induced in rare gas atoms. We estimated the difference of the induced dipole moment μ: μ of Xe atom on Ag(1 0 0) is 6% larger than that on Ag(1 1 1) and μ of Kr atom on Ag(1 0 0) is 14% larger than that on Ag(1 1 1).