Application of Electroless Cobalt Alloy Thin Films to Perpendicular Recording Media

Tetsuya Osaka, Ichiro Koiwa, Fumio Goto, Yoji Suganuma

Research output: Contribution to journalArticle

Abstract

Perpendicular magnetic recording media by means of electroless plating method were studied and developed. A plating bath A composed of ammoniacal malonate-malate complexing agents was initially developed by deciding the optimum conditions according to the effects of three main factors: concentrations of MnSO4 and NiSO4, and pH of the bath on the magnetic properties and crystal structure of the Co alloy-thin films obtained. Secondly, the bath composition was further optimized for CoSO4 concentration, NaH2PO2 concentration and bath temperature to obtain the revised bath B. The magnetic film plated from the bath B showed the lower coercivity Hc (⊥) and hence may be applied with the head having the narrower gap length for achieving the higher recording density. The films plated from the baths A and B were both composed of columnar structure of hep crystal with 0.05 μm diameter. It was observed that the grains were highly-oriented with a narrow dispersion of c-axis orientation normal to surface plane according to the rocking curve method. As a result of preparation of disks plated from baths A and B, the di-pulse waveforms which are characteristic of the perpendicular recording were observed at low bit recording density. The recording densities of D50 = 18500 FRPI and 25000 FRPI were obtained respectively for the disks when used with the ring-type head and the improved ring head having the narrower gap length.

Original languageEnglish
Pages (from-to)791-797
Number of pages7
JournalNippon Kagaku Kaishi
Volume1983
Issue number6
DOIs
Publication statusPublished - 1983

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Magnetic films
Cobalt alloys
Magnetic recording
Electroless plating
Coercive force
Plating
Magnetic properties
Crystal structure
Thin films
Crystals
Chemical analysis
Temperature
malic acid
malonic acid

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Application of Electroless Cobalt Alloy Thin Films to Perpendicular Recording Media. / Osaka, Tetsuya; Koiwa, Ichiro; Goto, Fumio; Suganuma, Yoji.

In: Nippon Kagaku Kaishi, Vol. 1983, No. 6, 1983, p. 791-797.

Research output: Contribution to journalArticle

Osaka, Tetsuya ; Koiwa, Ichiro ; Goto, Fumio ; Suganuma, Yoji. / Application of Electroless Cobalt Alloy Thin Films to Perpendicular Recording Media. In: Nippon Kagaku Kaishi. 1983 ; Vol. 1983, No. 6. pp. 791-797.
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