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公开(公告)号：CA2071348C
公开(公告)日：1998-05-19
申请号：CA2071348
申请日：1992-06-16
Applicant: IBM
Inventor： SHIMIZU TERUHISA , TAKAYAMA SHINJI
Abstract: This disclosure deals with a magnetic recording medium suitable for longitudinal recording, such medium having low medium noise and high coercivity. The medium includes a substrate and a magnetic layer formed on the substrate. The magnetic layer consists of a mixture of a magnetic alloy and a non-magnetic compound. The magnetic alloy is based on Co, Fe, or, Co-Fe, and the non-magnetic compound is selected from a group of oxides and nitrides such as, for example, silicon, zirconium, tantalum, boron, titanium and aluminum. The volume percentage of the non-magnetic compound in the entire volume of the mixed magnetic alloy and non-magnetic compound is preferably not less than about 2% and not more than about 30%.
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公开(公告)号：DE69115426D1
公开(公告)日：1996-01-25
申请号：DE69115426
申请日：1991-09-24
Applicant: IBM
Inventor： IIYORI HIDEO , TAKAYAMA SHINJI
Abstract: A magneto-optical medium (1) comprises first, second and third layers. The first layer has a thickness of not less than 1 nm and not more than 20 nm and is in the form of a rare earth-transition metal amorphous film including at least one rare earth element selected from a group consisting of Tb, Dy, and Gd and including at least one transition metal element selected from a group consisting of Fe and Co. The lecond layer (2) has a thickness of not less than 1 nm and not more than 20 nm and is in the form of either a rare earth-transition metal amorphous film including at least one rare earth element selected from a group consisting of ND and Pr and including at least one transition metal element selected from a group consisting of Fe and Co, or a crystalline film including at least one element selected from a group consisting of Fe and Co. The third layer (3) has a thickness of not less than 2 nm and is in the form of a rare earth-transition metal amorphous film including at least one rare earth element selected from a group consisting of Tb, Dy, and Gd and including at least one transition metal element selected from a group consisting of Fe and Co. The layers are laminated suceessively, with the second layer disposed between the first and third layers and with the first layer being the first to be penetrated by light. The medium has an advantageously large magneto-optical effect even at short wavelengths, reorients the magnetization in a direction perpendicular to the film surface, and permits high-density recording.
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公开(公告)号：MY131057A
公开(公告)日：2007-07-31
申请号：MYPI9101732
申请日：1991-09-25
Applicant: IBM
Inventor： IIYORI HIDEO , TAKAYAMA SHINJI
Abstract: MAGNETO-OPTICAL RECORDING MEDIA WITH HIGH KERR ROTATION AT SHORT WAVELENGTH HAVE BEEN INVENTED IN THE FORM OF THE TRIPLE-LAYERED STRUCTURE. FILMS WITH HIGH KERR ROTATION AT SHORT WAVELENGTH, BUT IN-PLANE ANISOTROPY, HAVE TO BE SANDWICHED BETWEEN (Tb, Dy) - (Fe, Co) AMORPHOUS FILMS WITH HIGH PERPENDICULAR ANISOTROPY. FURTHERMORE, IT HAS BEEN FOUND THAT THE THICKNESS FOR EACH LAYER IS CRITICAL. THE FIRST LAYER, WHICH A LASER BEAM PENETRATES FIRST, SHOULD BE THIN ENOUGH FOR THE LASER BEAM TO PENETRATE, BUT THICK ENOUGH TO GIVE STRONG EXCHANGE COUPLING TO THE SECOND LAYER. THE SECOND LAYER SHOULD BE THIN ENOUGH TO RECEIVE A STRONG EXCHANGE COUPLING FROM BOTH SIDE FILMS, BUT THICK ENOUGH TO GIVE HIGH KERR ROTATION. THE THIRD LAYER SHOULD BE THICK ENOUGH TO GIVE A STRONG EXCHANGE COUPLING TO THE SECOND LAYER. BY THIS TRIPLE-LAYERED APPROACH, THE INVENTORS HAVE SUCCEEDED IN MAKING FUTURE MAGNETO-OPTICAL MEDIA SUITABLE FOR HIGH RECORDING DENSITY.(FIG. 1)
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公开(公告)号：DE69222823D1
公开(公告)日：1997-11-27
申请号：DE69222823
申请日：1992-08-25
Applicant: IBM
Inventor： SHIMIZU TERUHISA , TAKAYAMA SHINJI
Abstract: A magnetic recording medium includes a substrate 1 and a magnetic layer 2 formed on the substrate 1. The magnetic layer 2 consists of a mixture of a magnetic alloy and a non-magnetic compound. The magnetic alloy is Co-based, Fe-based, or CoFe-based, and the non-magnetic compound is selected from a group consisting of oxides and nitrides. The volume percentage of the non-magnetic compound in the entire volume of the mixed magnetic alloy and non-magnetic compound is preferably between about 2% and about 30%. The magnetic recording disk is suitable for longitudinal recording, with low medium noise and high coercivity.
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公开(公告)号：HK24096A
公开(公告)日：1996-02-16
申请号：HK24096
申请日：1996-02-08
Applicant: IBM
Inventor： KATO YOSHIMINE , SHIMIZU TERUHISA , TAKAYAMA SHINJI , TANAKA HIROSHI
IPC: G11B11/10 , G11B11/105 , G11B7/24
Abstract: A magneto-optical recording medium is provided which has high magneto-optic effect even under a short-wavelength light, high anisotropy in the direction perpendicular to the film surface, and permits high-density recording, the medium having a first magnetic layer laminated onto a second magnetic layer, the first magnetic layer being a rare-earth-transition-metal amorphous film with mainly a light rare-earth element as rare-earth element, the light rare-earth element being at least one element selected from an element group consisting of Nd and Pr, and the second magnetic layer being a rare-earth-transition-metal amorphous film with at least one element selected from an element group consisting of Tb and Dy as rare-earth element.
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Patent Agency Ranking
公开(公告)号：DE69020992T2
公开(公告)日：1996-04-04
申请号：DE69020992
申请日：1990-09-17
Applicant: IBM
Inventor： KATO YOSHIMINE , SHIMIZU TERUHISA , TAKAYAMA SHINJI , TANAKA HIROSHI
IPC: G11B11/10 , G11B11/105 , G11B7/24
Abstract: A magneto-optical recording medium is provided which has high magneto-optic effect even under a short-wavelength light, high anisotropy in the direction perpendicular to the film surface, and permits high-density recording, the medium having a first magnetic layer laminated onto a second magnetic layer, the first magnetic layer being a rare-earth-transition-metal amorphous film with mainly a light rare-earth element as rare-earth element, the light rare-earth element being at least one element selected from an element group consisting of Nd and Pr, and the second magnetic layer being a rare-earth-transition-metal amorphous film with at least one element selected from an element group consisting of Tb and Dy as rare-earth element.
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公开(公告)号：CA2017300C
公开(公告)日：1994-05-17
申请号：CA2017300
申请日：1990-05-22
Applicant: IBM
Inventor： KATO YOSHIMINE , SHIMIZU TERUHISA , TAKAYAMA SHINJI , TANAKA HIROSHI
IPC: G11B11/10 , G11B11/105 , G11C13/06
Abstract: A magneto-optical recording medium has a first magnetic layer laminated on a second magnetic layer, the first magnetic layer, of (Nd, Pr)-transition-metal amorphous alloy systems, having high magneto-optical effect at short wavelengths but low perpendicular anisotropy, and the second magnetic layer, of (Tb, Dy)-transition-metal amorphous alloy systems, having low magneto-optical effect at short wavelengths but low perpendicular anisotropy. By exerting magnetic exchange coupling between these two layers on the said first layer to induce strong perpendicular anisotropy in it, a perpendicular magnetized magneto-optical recording medium is obtained that has overall high magneto-optical effect, even at short wavelengths.
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公开(公告)号：CA2071348A1
公开(公告)日：1993-03-07
申请号：CA2071348
申请日：1992-06-16
Applicant: IBM
Inventor： SHIMIZU TERUHISA , TAKAYAMA SHINJI
Abstract: A magnetic recording medium includes a substrate 1 and a magnetic layer 2 formed on the substrate 1. The magnetic layer 2 consists of a mixture of a magnetic alloy and a non-magnetic compound. The magnetic alloy is Co-based, Fe-based, or CoFe-based, and the non-magnetic compound is selected from a group consisting of oxides and nitrides. The volume percentage of the non-magnetic compound in the entire volume of the mixed magnetic alloy and non-magnetic compound is preferably between about 2% and about 30%. The magnetic recording disk is suitable for longitudinal recording, with low medium noise and high coercivity.
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公开(公告)号：SG44396A1
公开(公告)日：1997-12-19
申请号：SG1996000135
申请日：1992-08-25
Applicant: IBM
Inventor： SHIMIZU TERUHISA , TAKAYAMA SHINJI
Abstract: A magnetic recording medium includes a substrate 1 and a magnetic layer 2 formed on the substrate 1. The magnetic layer 2 consists of a mixture of a magnetic alloy and a non-magnetic compound. The magnetic alloy is Co-based, Fe-based, or CoFe-based, and the non-magnetic compound is selected from a group consisting of oxides and nitrides. The volume percentage of the non-magnetic compound in the entire volume of the mixed magnetic alloy and non-magnetic compound is preferably between about 2% and about 30%. The magnetic recording disk is suitable for longitudinal recording, with low medium noise and high coercivity.
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公开(公告)号：CA2051603C
公开(公告)日：1995-09-12
申请号：CA2051603
申请日：1991-09-17
Applicant: IBM
Inventor： IIYORI HIDEO , TAKAYAMA SHINJI
Abstract: A magneto-optical recording media is disclosed with high kerr rotation angle at short wavelengths in the form of a triple-layered structure. A film with a high Kerr rotation angle at a short wavelength is sandwiched between magneto-optical recording films with a high perpendicular magnetic anisotropy. The respective thickness of each layer is optimized to produce a triple-layered structure suitable for high recording density magneto-optical media.
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