Patent ID: 6383668
Filing Date: 2002-05-07
Classification: G11B,Y10S

Abstract:
A magnetic recording disk comprising:a substrate; a nonferromagnetic underlayer on the substrate; a host layer on the underlayer and comprising a first cobalt alloy ferromagnetic film having a thickness t1 and a magnetization M1, a nonferromagnetic spacer film of a material selected from the group consisting of ruthenium (Ru), chromium (Cr), rhodium (Rh), iridium (Ir), copper (Cu), and their alloys formed on and in contact with the first ferromagnetic film, and a second cobalt alloy ferromagnetic film formed on and in contact with the spacer film and having a thickness t2 and a magnetization M2, the spacer film having a thickness sufficient to induce the second ferromagnetic film to be exchange coupled antiferromagnetically to the first ferromagnetic film across the spacer film, and wherein the magnetic moments per unit area (M1Ã—t1) and (M2Ã—t2) of the first and second ferromagnetic films, respectively, are different from one another; a magnetic recording layer on and in contact with the second ferromagnetic film of the host layer, the magnetic recording layer having a composition different from the composition of the second ferromagnetic film and being ferromagnetically coupled with the second ferromagnetic film; and a protective overcoat formed on the magnetic recording layer.