Solid-solid surface adsorption of Eu2O3 on η-Al2O3 and SiO2 gel has been investigated using M?ssbauer spectroscopy and X-ray diffraction analysis. The results suggest that after appropriate treatment Eu2O3 disperses spontaneously onto the surface of both supporter materials. No indications of remaining crystalline Eu2O3 have been found below the limiting mono-layer concentration. In the case of η-Al2O3, it is suggested that below the limiting monolayer capacity Eu2O3 covers the surface in a disordered monolayer configuration. For higher Eu2O3 contents a second layer starts to appear with a structure similar to that of the bulk crystalline phase. In the case of SiO2 gel, it is suggested that the monolayer as well as the second layer configuration of Eu2O3 is highly disordered. It seems that the M?ssbauer parameters, isomer shift and linewidth allow additional insight into the surface layer structures formed by solid-solid adsorption.