Epitaxial Growth of Ni, Cu on bcc-Fe(001) and Ni on fcc-Au(001)

We have studied structural change of MBE grown Ni/Fe(001) and Cu/Fe(001) thin films using RHEED and X-ray diffraction measurements. Epitaxial bct-Ni film is grown initially up to 3 ML, then it changes to reconstructed c(2×2)-like structure for thicker film. 200 ML thick Ni film annealed at 520 K shows the clear formation of twinned domains of fcc-Ni{110}. The structural change of Cu films exhibits almost the same as Ni, except that it maintains bcc symmetry up to about 9 ML. Considering the lattice mismatch and the atomic volume, we discuss these differences of structural change between Ni and Cu. Epitaxial growth of Ni on fcc-Au(001) is also reported.