Patterned perpendicular magnetic recording medium with ultrathin noble metal interlayer

摘要

A bit-patterned media (BPM) magnetic recording disk has a cobalt (Co) alloy recording layer (RL), a ruthenium (Ru) containing underlayer (UL), and a noble metal film (NMF) as an interlayer between the RL and the UL. The RL is preferably oxide-free and is a Co alloy, like a CoPtCr alloy, with a hexagonal-close-packed (hcp) crystalline structure with its c-axis oriented substantially perpendicular to the plane of the RL. The NMF is an element from the Pt group (Pt, Pd, Rh, Ir) and Au, or an alloy of two or more of these elements, and has a thickness less than 3.0 nm, preferably between 0.3 and 1.0 nm. The NMF does not interrupt the epitaxial growth of the RL and has little to no effect on the distribution of the RL c-axis orientation. The NMF increases the coercivity (Hc) and perpendicular magnetic anisotropy constant (Ku) of the RL.

主权项

1. A patterned perpendicular magnetic recording medium comprising:
a substrate; a nonmagnetic Ru-containing underlayer on the substrate; a perpendicular magnetic recording layer of an alloy comprising cobalt and platinum; and a noble metal film between the Ru-containing layer and the magnetic recording layer, the noble metal film consisting of one or more of Pt, Pd, Rh, Ir and Au and having a thickness less than or equal to 3.0 nm; and wherein the magnetic recording layer is patterned into a plurality of discrete islands.