A sputter-deposited 80Cu20Ni (at.%) solid solution film was heated in situ using a step-wise annealing schedule within a transmission electron microscope to observe the grain boundary character evolution associated with grain growth. The grain size distribution broadened with increasing temperature with a corresponding increase in the Sigma 9 and Sigma 11 boundary fraction. Particular grains grew at a faster rate than others, as compared to a Cu film, and are attributed to Ni segregation to the grain boundaries. (C) 2014 Elsevier B.V. All rights reserved.