Preparation of Co–Cr–Pt alloy film with high perpendicular coercivity and large negative nucleation field

Abstract The magnetic properties of Co–Cr–Pt thin films for perpendicular magnetic recording media were studied in terms of the film composition. A very high perpendicular coercivity (Hc ⊥ ) greater than 5000 Oe was obtained at 13–18 at% Cr content and 12–22 at% Pt content. Perpendicular squareness (SQ ⊥ ) and the maximum nucleation field ( H N ) were equal to unity and −2500 Oe, respectively. Co–Cr–Pt double layered medium has also showed SQ ⊥ of unity and large negative H N .