Patent ID: 7282277

Claim:
A magnetic recording medium including Cu-containing magnetic recording layers (CuML) comprised of a stacked bi-layer structure [Cr-rich CuML/Cr-poor CuML] n , where n=1 to 10 and said [Cr-rich CuML/Cr-poor CuML] bi-layer is comprised of a Cr-rich, Cu-containing magnetic recording layer (Cr-rich CuML) that includes a Cr-rich magnetic alloy material selected from the group consisting of: (a) a CoCrPtBCu alloy having a composition represented by the formula Co 100-x-y-z-α Cr x Pt y B z Cu α , wherein 16≦x≦20, 0<y≦30, 0<z≦24, and 0<α≦10; (b) a CoCrPtBCu alloy having a composition represented by the formula Co 100-x-y-z-α Cr x Pt y B z Cu α , wherein 16≦x≦30, 0<y≦30, 7<z≦24, and 0<α≦10; and (c) a CoCrTaCu alloy having a composition represented by the formula Co 100-x-y-α Cr x Ta y Cu α , wherein 16≦x<30, containing up to 8 at. % Ta, and up to 10 at. % Cu; and a Cr-poor, Cu-containing magnetic recording layer (Cr-poor CuML) that includes a Cr-poor magnetic alloy material selected from the group consisting of: (d) a CoCrPtBCu alloy having a composition represented by the formula Co 100-x-y-z-α Cr x Pt y B z Cu α , wherein 0<x<16, 0<y≦30, 0<z≦24, and 0<α≦10; (e) a CoCrPtBCu alloy having a composition represented by the formula Co 100-x-y-z-α Cr x Pt y B z Cu α , wherein 0<x<16, 0<y≦30, 7<z≦24, and 0<α≦10; and (f) a CoCrTaCu alloy having a composition represented by the formula Co 100-x-y-α Cr x Ta y Cu α , wherein 0<x<16, containing up to 8 at. % Ta, and up to 10 at. % Cu.