L10 FePt films epitaxially grown on MgO substrates with or without a Cr underlayer

FePt and FePt/Cr films were epitaxially grown on MgO (2 0 0) substrates at 350 1C by DC magnetron sputtering. The structural properties and epitaxial relationship are investigated by high-resolution X-ray diffraction (XRD). The XRD spectra revealed that both FePt and FePt/Cr films had a (0 0 1) preferred orientation. However, FePt films with Cr underlayers had a larger a and a smaller c than those of the samples without Cr underlayers. Furthermore, the FePt (0 0 1) peak characterized by its rocking curves became less pronounced when the Cr underlayer was applied. The off-spectra from the MgO (1 1 1), Cr (1 0 1) and FePt (1 1 1) demonstrated that the epitaxial relationship between the FePt film, Cr underlayer and MgO substrate was confirmed to be FePt (0 0 1)o1004 || Cr (1 0 0)o1 1 04 || MgO (1 0 0)o0 0 14. The domain size and Ms decreased when the Cr underlayer was applied due to the diffusion of Cr and the existence of the initial layer between Cr and FePt layers. r 2006 Elsevier B.V. All rights reserved. PACS: 68.55.Jk; 75.50.Ss