Patent ID: 6641901
Filing Date: 2003-11-04
Classification: G11B,Y10T

Abstract:
Perpendicular magnetic recording media, comprising:a non-magnetic substrate; a first recording layer provided on the non-magnetic substrate and provided with perpendicular magnetic anisotropy; a second recording layer laminated on the first recording layer and provided with perpendicular magnetic anisotropy, wherein: the exchange stiffness constant showing the magnitude of magnetic exchange interaction between grains of the first recording layer is 0.05Ã—10âˆ’11 J/m or less; the exchange stiffness constant showing the magnitude of magnetic exchange interaction between grains of the second recording layer is a range of 0.15Ã—10âˆ’11 J/m to 0.8Ã—10âˆ’11 J/m; a sum of a thickness of the first recording layer and thickness of the second recording layer is 10 to 100 nm; and a ratio of the thickness of the second recording layer to the thickness of the first recording layer is in a range of 0.5 to 1.0.