Grazing-incidence x-ray diffraction characterization of Co-Pt magneto-optical thin films

The microstructures of epitaxial CoxPt1-x films (x≊0.25 and 0.5) and the orientation relationships with sapphire (0001) single-crystal substrates were determined by grazing-incidence x-ray diffraction. The epitaxial relationships between the CoPt3 film and its substrate are CoPt3[11̄0]∥Al2O 3[303̄0] and CoPt3(111)∥Al2O 3(0001). A significant amount of the ordered L12 phase was detected in CoPt3. The degree of long-range order in CoPt 3 was 0.3, and the average domain size of the ordered phase was 80 Å. The CoPt film had two domains related by a 30°in-plane rotation. The epitaxial relationships between the CoPt film and its substrate were CoPt[100]∥Al2O3[303̄0] and CoPt(011)∥Al 2O3(0001) for domain A and CoPt[100]∥Al 2O3[112̄0] and CoPt(011)∥Al2O 3(0001) for domain B. Domain A was found to be dominant and/or had a higher degree of long-range order than domain B.