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Laminated magnetic recording medium

A technology of magnetic recording medium and magnetic recording layer, applied in magnetic recording, data recording, plating of superimposed layers, etc., can solve problems such as high bit error rate

Inactive Publication Date: 2006-02-15
HITACHI GLOBAL STORAGE TECH NETHERLANDS BV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Thus, higher media noise leads to higher bit error rate

Method used

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  • Laminated magnetic recording medium
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Embodiment Construction

[0019] Magnetic recording media have a recording layer formed of two or more ferromagnetic films that are antiferromagnetically (AF) exchanged with their adjacent ferromagnetic films by one or more nonferromagnetic spacer films coupling. figure 1 A recording layer 10 consisting of two ferromagnetic films 12, 14 separated by a non-ferromagnetic spacer film 16 is schematically shown in . The thickness and composition of the nonferromagnetic spacer film 16 are chosen such that the magnetic moments 22, 24 of adjacent films 12, 14, respectively, are AF coupled through the nonferromagnetic spacer film 16 and are antiparallel at zero applied magnetic field.

[0020] AF coupling of ferromagnetic films via non-ferromagnetic transition metal spacers has been extensively studied and described in the literature. Generally, as the thickness of the spacer film increases, the exchange coupling oscillates from ferromagnetic to antiferromagnetic. Parkin et al. describe in "Oscillations in Ex...

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Abstract

A laminated magnetic recording medium for data storage uses a magnetic recording layer having at least two antiferromagnetically-coupled (AFC) layers spaced apart by a nonferromagnetic spacer layer. Each AFC layer is formed as two ferromagnetic films antiferromagnetically coupled together across an antiferromagnetically coupling film that has a composition and thickness to induce antiferromagnetic coupling of the second film to the first film. The magnetic moments of the two antiferromagnetically-coupled films in each AFC layer are oriented antiparallel, and thus the net remanent magnetization-thickness product (Mrt) of each AFC layer is the difference in the Mrt values of the two ferromagnetic films. The nonferromagnetic spacer layer between neighbouring AFC layers has a composition and thickness to prevent any antiferromagnetic coupling of the ferromagnetic films of one AFC layer with the ferromagnetic films of the neighbouring AFC layer.

Description

technical field [0001] The present invention relates generally to magnetic recording media, and more particularly to thermally stable high density media. Background technique [0002] Conventional magnetic recording media, such as magnetic recording disks in hard disk drives, generally use a granular ferromagnetic layer such as a sputter-deposited cobalt-platinum (Copt) alloy as the recording medium. Each magnetic domain in the magnetic layer consists of many small magnetic grains. The transition regions between the magnetic domains represent "bits" of recorded data. Conventional hard disks of this type are described in US Patents US478959A and US5523173A of IBM Corporation. [0003] As the storage density of the magnetic recording disk increases, the product of the residual magnetization Mr (magnetic moment per unit volume of ferromagnetic material) and the thickness of the magnetic layer t decreases. Similarly, the coercive field or coercive force (Hc) of the magnetic l...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B5/66G11B5/65C23C28/00C23C28/02G11B5/64G11B5/673G11B5/708G11B5/738H01F10/26
CPCG11B5/66C23C28/023C23C28/42C23C28/021Y10T428/2495Y10T428/24942G11B5/678Y10S428/90
Inventor 霍亚·范多埃里克·E·富勒顿戴维·T·马古利斯哈尔·J·罗森
Owner HITACHI GLOBAL STORAGE TECH NETHERLANDS BV
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