High-coercivity longitudinal recording medium prepared using non-heating process

2001 ◽  
Vol 37 (4) ◽  
pp. 1488-1490 ◽  
Author(s):  
H. Ohmori ◽  
A. Itoh ◽  
A. Maesaka ◽  
A. Okabe
Keyword(s):  
High Coercivity ◽  
Heating Process ◽  
Recording Medium ◽  
Longitudinal Recording

scholarly journals High Coercivity Recording Media Prepared Using Non-heating Process.

2001 ◽  
Vol 25 (4−2) ◽  
pp. 607-610 ◽  
Author(s):  
H. Ohmori ◽  
A. Itoh ◽  
A. Maesaka
Keyword(s):  
High Coercivity ◽  
Heating Process ◽  
Recording Media

Microstructure and magnetic Structure of Co-based thin-film recording medium

1993 ◽  
Vol 51 ◽  
pp. 1012-1013
Author(s):  
M. Futamoto ◽  
Y. Honda ◽  
N. Inaba ◽  
Y. Matsuda ◽  
M. Suzuki
Keyword(s):  
Thin Film ◽  
Layered Medium ◽  
Average Distance ◽  
Magnetic Coupling ◽  
Film Plane ◽  
Recording Medium ◽  
Plan View ◽  
Sem Micrograph ◽  
Longitudinal Recording ◽  
The Relationship

Knowledge of the relationship between microstructure and microscopic magnetization configuration is strongly required to improve Co-based thin film media. The purpose of this paper is to report some of these properties measured for a thin film longitudinal recording medium and to discuss their inter-relationship.Figure 1 shows an SEM micrograph of fractured cross-section of CoCrPt/CoCrPtSi dual-layered medium which was used to demonstrate the feasibility of 2 Gb/in2 magnetic recording. The Cr underlayer is used to control the orientation, size, and distribution of magnetic crystals. Magnetic crystal grains, whose size ranges between 20-30nm, form chain-like clusters consisting of several crystals as shown in the plan-view TEM micrograph(Fig.2). Neighboring clusters are separated physically with an average distance of 3nm. Magnetic separation among magnetic crystals and/or clusters is important to reduce the medium noise which is related to magnetic coupling between crystals. The crystalline easy axes of the grains are randomly oriented in the film plane.

CoSm‐based high‐coercivity thin films for longitudinal recording

1991 ◽  
Vol 69 (8) ◽  
pp. 5175-5177 ◽  
Author(s):  
E. M. T. Velu ◽  
D. N. Lambeth
Keyword(s):  
Thin Films ◽  
High Coercivity ◽  
Longitudinal Recording

Lorentz electron microscopy of magnetic domains in rapidly solidified and annealed Pt-Co-B alloys

1991 ◽  
Vol 49 ◽  
pp. 784-785
Author(s):  
N. Qiu ◽  
J. E. Wittig
Keyword(s):  
Rapid Solidification ◽  
Ion Beam ◽  
Magnetic Behavior ◽  
High Coercivity ◽  
Magnetic Domains ◽  
Beam Angle ◽  
Tem Analysis ◽  
Intrinsic Coercivity ◽  
Hard Magnets ◽  
Rapidly Solidified

PtCo hard magnets have specialized applications owing to their relatively high coercivity combined with corrosion resistance and ductility. Increased intrinsic coercivity has been recently obtained by rapid solidification processing of PtCo alloys containing boron. After rapid solidification by double anvil splat quenching and subsequent annealing for 30 minutes at 650°C, an alloy with composition Pt42Co45B13 (at.%) exhibited intrinsic coercivity up to 14kOe. This represents a significant improvement compared to the average coercivities in conventional binary PtCo alloys of 5 to 8 kOe.Rapidly solidified specimens of Pt42Co45B13 (at.%) were annealed at 650°C and 800°C for 30 minutes. The magnetic behavior was characterized by measuring the coercive force (Hc). Samples for TEM analysis were mechanically thinned to 100 μm, dimpled to about 30 nm, and ion milled to electron transparency in a Gatan Duomill at 5 kV and 1 mA gun current. The incident ion beam angle was set at 15° and the samples were liquid nitrogen cooled during milling. These samples were analyzed with a Philips CM20T TEM/STEM operated at 200 kV.

Transmission Electron Microscopy of oriented Co84Cr14Ta2 thin films for longitudinal magnetic recording

1991 ◽  
Vol 49 ◽  
pp. 756-757
Author(s):  
T. P. Nolan
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Cost ◽  
Low Noise ◽  
Information Storage ◽  
High Coercivity ◽  
Magnetic Alloy ◽  
Magnetic Media ◽  
Transmission Electron

Thin film magnetic media are being used as low cost, high density forms of information storage. The development of this technology requires the study, at the sub-micron level, of morphological, crystallographic, and magnetic properties, throughout the depth of the deposited films. As the microstructure becomes increasingly fine, widi grain sizes approaching 100Å, the unique characterization capabilities of transmission electron microscopy (TEM) have become indispensable to the analysis of such thin film magnetic media.Films were deposited at 225°C, on two NiP plated Al substrates, one polished, and one circumferentially textured with a mean roughness of 55Å. Three layers, a 750Å chromium underlayer, a 600Å layer of magnetic alloy of composition Co84Cr14Ta2, and a 300Å amorphous carbon overcoat were then sputter deposited using a dc magnetron system at a power of 1kW, in a chamber evacuated below 10-6 torr and filled to 12μm Ar pressure. The textured medium is presently used in industry owing to its high coercivity, Hc, and relatively low noise. One important feature is that the coercivity in the circumferential read/write direction is significandy higher than that in the radial direction.

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