Buffer layer effect on magnetic domain structure and coercivity in epitaxial Co/Pt multilayers

Multilayers of Co/Pt on different buffer layers have been made using molecu lar beam epitaxy. Observation of magnetic domains on Co/Pt multilayers indi cates that the size of domains as well as their growth strongly depend on t he buffer layers. The layer structures used in this study are Al2O3(11-20)/ y/[Co(0.3 nm)/Pt(1 nm)] x 30, where y represents Mo(20 nm), Mo(20 nm)/Pt(20 nm), and Pt(20 nm). The growth of domains all show wall motion dominate be havior. Domain displacement of samples with a Mo buffer layer appeared to g row along the crystalline orientation. The film with no buffer layer showed the most irregular boundary domains compared to other films. The average d omain width was between 1.56 and 0.80 mu m. In addition, we have found that the coercivity of Co/Pt him was enhanced particularly by using a Mo/Pt buf fer layer. (C) 1999 Elsevier Science B.V. All rights reserved.