Poly- and single-crystal thin films of U-Mo alloys have been grown both on glass and sapphire substrates by ultra-high vacuum magnetron sputtering. X-ray and Electron Backscatter Diffraction data indicate that for single-crystal U1-xMox alloys, the pure cubic uranium gamma-phase exists for x >= 0.22 (10 wt.% Mo). Below 10 wt.% Mo concentration, the resulting thin film alloys exhibited a mixed alpha-gamma uranium phase composition. (C) 2013 Published by Elsevier B.V.