The relative sputtering rates of Ag and Cu from the Ag/Cu eutectic (60% Ag‐40% Cu by atoms) were measured by means of the spectroscopic emission technique. The targets were bombarded by 100‐eV Ar ions for target temperatures in the range of 80° to 285°C. At low target temperatures, the Ag and Cu sputtering yields vary with time of sputtering according to a simple sputtering model. However, at the higher temperatures surprisingly large differences were observed which could not be explained by a simple model. For example, Ag/Cu sputtering ratio variations greater than a factor of 10 were observed. After prolonged sputtering in the high‐temperature range, a thick surface layer (∼1 &mgr;) developed which was highly enriched in Cu. A model based on surface diffusion of Ag on Cu is proposed to explain the results.