Sm(Co,Cu)(5) epitaxial thin film with c-axis perpendicular to the substrate surface is successfully prepared on Al2O3(0 0 0 1) substrate employing Cu(1 1 1) single-crystal underlayer, while Sm-Co amorphous layers grow on Ru(0 0 0 1) and Co(0 0 0 1) underlayers as well as when deposited directly on Al2O3(0 0 0 1) substrate. The Sm(Co,Cu)(5) epitaxial thin film has a bi-crystalline structure whose orientations are rotated around the film normal by 30 degrees each other. The Cu underlayer plays an important role in assisting the formation of Sm(Co,Cu)(5) epitaxial thin film. (C) 2009 Elsevier B.V. All rights reserved.