CoCrPtB alloys with increased boron content and method of producing same

A magnetic recording medium comprising:

• a) a substrate;
• b) a metal under-layer on said substrate said, under-layer having a body-centered-cubic lattice structure;
• c) a Co alloy nucleation layer deposited on said under-layer wherein said Co alloy nucleation layer is 1 to 50 Angstroms thick;
• d) a magnetic layer deposited on said Co alloy nucleation layer, said magnetic layer comprising a Co alloy comprising Crx, Pty, and Bz wherein 0≦x≦30, 0≦y≦40 and 10≦z≦25 atomic percent, and 25≦(x+y+z)≦60.

A method for making a magnetic storage medium comprising:

• a) providing a substrate;
• b) depositing on said substrate an under-layer selected from the group consisting of chromium, ruthenium, chromium alloy and ruthenium alloy;
• c) depositing on said under-layer a nucleation layer comprising a Co alloy comprising Crx, Pty, and Bz wherein 15≦x≦40, 0≦y≦15 and 0≦z≦10 atomic percent, and 25≦(x+y+z)≦50;
• d) and depositing on said nucleation layer a magnetic layer comprising a Co alloy comprising Crz, Pty, and Bz wherein 0≦x≦30, 0≦y≦40 and 10≦z≦25 atomic percent, and 25≦(x+y+z)≦60.