Formation of SmFe5(0001) ordered alloy thin films on Cu(111) single-crystal underlayers

SmFe5(0001) single-crystal thin films are prepared by molecular beam epitaxy employing Cu(111) single-crystal underlayers on MgO(111) substrates. The Cu atoms diffuse into the Sm-Fe layer and substitute the Fe sites in SmFe5 structure forming an alloy compound of Sm(Fe,Cu)5. The Sm(Fe,Cu)5 film is more Cu enriched with increasing the substrate temperature. The Cu underlayer plays an important role in assisting the formation of the ordered phase.