INVESTIGATION OF CHEMICAL ORDERING IN MBE-GROWN COXPT1-X FILMS BY X-RAY-DIFFRACTION AND HIGH-RESOLUTION TRANSMISSION ELECTRON-MICROSCOPY

From X-ray diffraction (XRD) measurements, long-range chemical orderin g along the growth direction is observed in epitaxial(0001) CoxPt1-x ( x similar to 0.8) alloy films. Such ordering increases with the deposi tion temperature up to 690 K, together with the volume fraction of hcp stacking sequence, and also depends on the crystalline quality of the epitaxial film. In contrast, no chemical order was detected in the (0 001) planes. Digital processing of cross-sectional high-resolution tra nsmission electron microscopy (HRTEM) images shows that a chemical ord er along the growth direction [111] also exists in the minority fcc ph ase of a Co82Pt18 film grown at 690 K. (C) 1998 Published by Elsevier Science S.A.