公开(公告)号：WO0173762A3

公开(公告)日：2002-04-04

申请号：PCT/GB0101180

申请日：2001-03-19

Applicant: IBM ,  IBM UK

Inventor： FULLERTON ERIC EDWARD ,  MARGULIES DAVID THOMAS ,  MARINERO ERNESTO ESTEBAN ,  SCHABES MANFRED ERNST

IPC: G11B5/738 ,  G11B5/66 ,  G11B5/72 ,  G11B5/82 ,  H01F10/16

CPC classification number: G11B5/66 ,  Y10S428/90

Abstract: A magnetic recording disk has a magnetic recording layer formed on a special multilayered "host" layer (30). The host layer comprises at least two ferromagnetic films (32, 34) that are exchange-coupled antiferromagnetically (AF) to one another across a nonferromagnetic spacer film so that their magnetic moments are oriented antiparallel. The magnetic recording layer (25) has a different composition from the top ferromagnetic film in the host layer and is ferromagnetically coupled to the top ferromagnetic film of the host layer.

Abstract translation: 磁记录盘具有形成在特殊的多层“主体”层（30）上的磁记录层。 主体层包括至少两个铁磁膜（32,34），其通过非铁磁隔离膜彼此交互耦合反铁磁（AF），使得它们的磁矩反平行取向。 磁记录层（25）与主体层中的顶部铁磁膜具有不同的组成，并且与主体层的顶部铁磁膜铁磁耦合。

公开(公告)号：JP2001148110A

公开(公告)日：2001-05-29

申请号：JP2000307398

申请日：2000-10-06

Applicant: IBM

Inventor： CAREY MATTHEW JOSEPH ,  FULLERTON ERIC EDWARD ,  GURNEY BRUCE ALVIN ,  ROSEN HAL JERVIS ,  SCHABES MANFRED ERNST

IPC: G11B5/708 ,  C23C28/00 ,  C23C28/02 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/673 ,  G11B5/738 ,  H01F10/26

Abstract: PROBLEM TO BE SOLVED: To provide a magnetic recording medium for keeping good thermal stability and SNR and supporting ultra high-density recording. SOLUTION: This magnetic recording medium for a data storage device is constituted of at least two magnetic recording layers of ferromagnetic films, which are adhered to each other in an antiferromagnetic manner, while interposing a nonferromagnetic spacer film. Magnetic moment of one ferromagnetic film works in the direction antiparallel to that of the magnetic moment of the other ferromagnetic film. The balanced magnetic moment is shown as the difference between Mrt values of two ferromagnetic films, when the magnetic moment is shown by net product (Mrt) of residual magnetism (Mr) and thickness (t) in the magnetic recording layer. The decrease in Mrt is achieved, while the thermal stability of the recording medium is not deteriorated, because the volume of particles in ferromagnetic films adhered to each other in an antiferromagnetic manner is increased constructively. Very sharp magnetic transitions can be achieved by the reduced antimagnetic field and higher density of the bit lines can be obtained in this medium as a result.

公开(公告)号：CA2398950A1

公开(公告)日：2001-10-04

申请号：CA2398950

申请日：2001-03-19

Applicant: IBM

Inventor： FULLERTON ERIC EDWARD ,  MARGULIES DAVID THOMAS ,  MARINERO ERNESTO ESTEBAN ,  SCHABES MANFRED ERNST

IPC: G11B5/738 ,  G11B5/66 ,  G11B5/72 ,  G11B5/82 ,  H01F10/16

Abstract: A magnetic recording disk has a magnetic recording layer formed on a special multilayered "host" layer (30). The host layer comprises at least two ferromagnetic films (32, 34) that are exchange-coupled antiferromagnetically (AF) to one another across a nonferromagnetic spacer film so that their magnetic moments are oriented antiparallel. The magnetic recording layer (25 ) has a different composition from the top ferromagnetic film in the host laye r and is ferromagnetically coupled to the top ferromagnetic film of the host layer.

公开(公告)号：GB2355018B

公开(公告)日：2004-02-11

申请号：GB0015023

申请日：2000-06-21

Applicant: IBM

Inventor： CAREY MATTHEW JOSEPH ,  FULLERTON ERIC EDWARD ,  GURNEY BRUCE ALVIN ,  ROSEN HAL JERVIS ,  SCHABES MANFRED ERNST

IPC: G11B5/708 ,  C23C28/00 ,  C23C28/02 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/673 ,  G11B5/738 ,  H01F10/26 ,  C23C14/14 ,  C23C14/16 ,  G11B5/62 ,  G11B5/84

Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film. The magnetic moments of the two antiferromagnetically-coupled films are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in the thermal stability of the recording medium because the volumes of the grains in the antiferromagnetically-coupled films add constructively. In a magnetic recording rigid disk application, the magnetic layer comprises two ferromagnetic films, each a granular film of a sputter deposited CoPtCrB alloy, separated by a Ru spacer film having a thickness to maximize the antiferromagnetic exchange coupling between the two CoPtCrB films. One of the ferromagnetic films is made thicker than the other, but the thicknesses are chosen so that the net moment in zero applied magnetic field is low, but nonzero.

公开(公告)号：AU4088001A

公开(公告)日：2001-10-08

申请号：AU4088001

申请日：2001-03-19

Applicant: IBM

Inventor： MARGULIES DAVID THOMAS ,  MARINERO ERNESTO ESTEBAN ,  SCHABES MANFRED ERNST

IPC: G11B5/738 ,  G11B5/66 ,  G11B5/72 ,  G11B5/82 ,  H01F10/16 ,  G11B5/00

Abstract: A magnetic recording disk has a magnetic recording layer formed on a special multilayered "host" layer. The host layer is a "synthetic antiferromagnetically", i.e., at least two ferromagnetic films that are exchange-coupled antiferromagnetically (AF) to one another across a nonferromagnetic spacer film so that their magnetic moments are oriented antiparallel. The magnetic recording layer has a different composition from the top ferromagnetic film in the host layer and is ferromagnetically coupled to the top ferromagnetic film of the host layer. The magnetic volume V of the composite structure (magnetic recording layer and host layer) that determines the thermal stability will be approximately the sum of the volumes of the grains in the magnetic recording layer and the AF-coupled ferromagnetic films of the host layer. However, the magnetic moment of the composite structure is primarily just the moment from the magnetic recording layer because the host layer is designed to have essentially no net magnetic moment.

公开(公告)号：GB2355018A

公开(公告)日：2001-04-11

申请号：GB0015023

申请日：2000-06-21

Applicant: IBM

Inventor： CAREY MATTHEW JOSEPH ,  FULLERTON ERIC EDWARD ,  GURNEY BRUCE ALVIN ,  ROSEN HAL JERVIS ,  SCHABES MANFRED ERNST

IPC: G11B5/708 ,  C23C28/00 ,  C23C28/02 ,  G11B5/64 ,  G11B5/65 ,  G11B5/66 ,  G11B5/673 ,  G11B5/738 ,  H01F10/26 ,  C23C14/14 ,  C23C14/16 ,  G11B5/62 ,  G11B5/84

Abstract: A magnetic recording medium for data storage uses a magnetic recording layer having at least two ferromagnetic films antiferromagnetically coupled together across a nonferromagnetic spacer film. The magnetic moments of the two antiferromagnetically-coupled films are oriented antiparallel, and thus the net remanent magnetisation-thickness product (Mrt) of the recording layer is the difference in the Mrt values of the two ferromagnetic films. This reduction in Mrt is accomplished without a reduction in the thermal stability of the recording medium because the volumes of the grains in the antiferromagnetically-coupled films add constructively. In a magnetic recording rigid disk application, the magnetic layer comprises two ferromagnetic films, each a granular film of a sputter deposited coPtCrB alloy, separated by a Ru spacer film having a thickness to maximise the antiferromagnetic exchange coupling between the two CoPtCrB films. One of the ferromagnetic films is made thicker than the other, but the thicknesses are chosen so that the net moment in zero applied magnetic field is low, but nonzero. In general the first and second ferromagnetic films are made of a material selected from Co, Fe, Ni and their alloys. Apart from ruthenium the spacer film may be formed of Cr, Rh, Ir, Cu and their alloys. The medium may be in the form of a disk which has an underlayer on the substrate and a protective overcoat formed on the magnetic recording layer.