CoPtB(O) alloy films as new perpendicular recording media

Journal Article · Tue May 01 00:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.346052· OSTI ID:6947970

Hayashi, K; Hayakawa, M; Ohmori, H; Okabe, A; Aso, K ^[1]

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1. Sony Corporation Research Center, 174 Fujitsuka-cho, Hodogaya-ku, Yokohama 240, Japan (JP)

In search of new hard magnetic materials with high saturation magnetization and large coercivity, a comprehensive study was made on numerous Co- and CoPt-base crystalline alloys by means of sputtering techniques. It revealed that a newly found CoPtB(O) alloy system possessed excellent hard magnetic properties with remarkably large perpendicular coercivity and high saturation magnetization. This new alloy film, deposited onto room temperature substrates, shows the magnetic properties of 4{pi}{ital M}{sub {ital s}}=12 kG, {ital H}{sup {perpendicular}}{sub {ital c}}=4000 Oe, and perpendicular anisotropy field {ital H}{sub {ital k}}=22 kOe. These values are superior to those of prevailing materials such as CoCr perpendicular and CoPt or CoNi longitudinal recording media. The typical composition is Co{sub 69}Pt{sub 20}B{sub 6}O{sub 5} (at. %), and oxygen plays a momentous role on the coercivity in this alloy film. As a magnetic recording medium, a write/read experiment of this film shows that the readout signal has a +9 dB peak-to-peak amplitude compared with that of metal particle tape at 1 {mu}m wavelength and has +10 dB compared with that of a CoCr perpendicular medium at 0.5 {mu}m wavelength.

• OSTI ID: 6947970
• Journal Information: Journal of Applied Physics; (USA), Vol. 67:9; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BORON OXIDES
MAGNETIC PROPERTIES
COBALT OXIDES
PLATINUM OXIDES
ANISOTROPY
COERCIVE FORCE
FILMS
MAGNETIC STORAGE DEVICES
MAGNETIZATION
SATURATION
BORON COMPOUNDS
CHALCOGENIDES
COBALT COMPOUNDS
MEMORY DEVICES
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
PLATINUM COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties