公开(公告)号：JP2000207727A

公开(公告)日：2000-07-28

申请号：JP35777399

申请日：1999-12-16

Applicant: IBM

Inventor： AHLERT RICHARD H ,  JAMES KENT HOWARD ,  LAMBERT STEVEN E ,  SANDERS IAN L

IPC: G11B5/673 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/716 ,  G11B5/738

Abstract: PROBLEM TO BE SOLVED: To reduce inherent medium noise significantly under a high line recording density by employing a laminate structure of a relatively thin CoPt alloy magnetic film or a CoNi alloy magnetic film separated by a relatively thin nonmagnetic spacer film. SOLUTION: Surface of a substrate is cleaned by RF discharge and a lower layer (300-400 Å thick) of Mo, Cr or CrV is attached by sputtering before being laminated with a magnetic layer. Subsequently, a magnetic layer (magnetic film and spacer) is attached through sputtering by changing the sputtering source to form a laminate structure. Effect of lamination on a signal is minimized and noise reduction is enhanced significantly as the number of laminated films increases. A laminate structure CoPt alloy disc thus produced exhibits excellent low noise characteristic as compared with a single thick CoPt alloy film.

公开(公告)号：CA1269894A

公开(公告)日：1990-06-05

申请号：CA532014

申请日：1987-03-13

Applicant: IBM

Inventor： AHLERT RICHARD H ,  HOWARD JAMES K ,  LIM GRACE S

IPC: G11B5/66 ,  G11B5/64 ,  G11B5/73 ,  G11B5/738 ,  G11B5/82 ,  G11B5/62 ,  H01F41/14 ,  H01F10/16

Abstract: An improved cobalt-platinum (CoPt) thin film metal alloy media for horizontal magnetic recording has a coercivity substantially greater than prior CoPt thin film metal alloy media. A tungsten underlayer between the substrate and the CoPt magnetic layer improves the coercivity above that of media with conventional underlayers, such as chromium. The coercivity of the CoPt layer can be increased even further if the CoPt film is deposited in such a manner as to form an intermetallic compound of Co3W in the interface region between the tungsten underlayer and the CoPt magnetic layer. The tungsten underlayer also improves the magnetic properties of the media when the magnetic layer is an alloy of cobalt-platinum-chromium (CoPtCr).

公开(公告)号：CA1269895A

公开(公告)日：1990-06-05

申请号：CA532016

申请日：1987-03-13

Applicant: IBM

Inventor： AHLERT RICHARD H ,  HOWARD JAMES K ,  LIM GRACE S

IPC: G11B5/66 ,  G11B5/64 ,  G11B5/65 ,  G11B5/706 ,  G11B5/73 ,  G11B5/738 ,  B32B15/00

Abstract: A vertical magnetic recording medium is formed of multiple layers, each layer comprising a cobalt-platinum (CoPt) magnetic film formed on a hexagonal-close-packed (HCP) nucleating film. The thickness of each CoPt film in each layer is sufficiently thin to assure that the film has perpendicular magnetic anisotropy. The magnetic properties of the multilayered magnetic film structure can be varied by varying the thicknesses of the individual films and the number of layers.