MISCIBILITY WITHIN MONOLAYER AG-CU FILMS ON RU(0001)

We study the properties of the quasi-2D system of Ag-Cu monolayers on Ru(0001) by means of thermal desorption spectroscopy (TDS). In addition, with a lattice gas model for alloy films on triangular substrate structures, we simulate TD spectra using Monte Carlo methods. Experimental and simulated spectra are presented and discussed with emphasis on the miscibility properties of Ag and Cu on Ru(0001). We conclude that on this surface the Ag-Cu interactions are attractive and, according to the interaction parameters extracted from the simulations, of the same order of magnitude as the (attractive) Ag-Ag and Cu-Cu interactions. Therefore Ag and Cu appear to be miscible on Ru(0001).