The pseudobinary systems RZn2-RAl2, RZn2-RGa2, with R = Ce, Sm, Gd, Er, RCu2-RGa2 with R = Ce, Sm, and ErNiGa-ErGa2 were studied to determine the structure of the intermediate phases and the extension of their homogeneity ranges. In all cases, solid solutions were formed in which there were at most two intermediate phases, with the structures of types CaIn2 and CeCd2. The corresponding composition ranges increase, moving from the cerium to the samarium, gadolinium and erbium systems. The influence of the electron concentration is discussed.
