Structures of Cr-Cu and Mo-Ag thin films coevaporated onto various substrates have been investigated by transmission electron microscopy and x-ray diffractometry. Also studied are their grain sizes, lattice constants, electrical resistivities, and the thermal stabilities in association with the film composition and the substrate temperature. It is found that Cu is soluble in the Cr lattice up to 60% when coevaporated at room temperature forming a metastable phase. At elevated temperatures, the solubility decreases slowly and the equilibrium phase, a mixture of fcc Cu and bcc Cr phases, starts to form at the 25% Cr/75% Cu composition region. The bcc metastable phase formation is preferred to the fcc phase when these two elements are coevaporated with a 1:1 ratio. Substrate orientation is found to have very little effect in determining the resulting crystal structure of the film. The same results have been found in the case of Ag-Mo coevaporation. © 1988, American Vacuum Society. All rights reserved.