Perpendicular magnetic recording medium and method for making

Details Perpendicular magnetic recording medium and method for making Perpendicular magnetic recording medium and method for making

Filed on

1992-03-20

Date issued

1996-06-11

Examiner

Kiliman, L.

Patent Class

Stock material or miscellaneous articles

SubClass

Structurally defined web or sheet

SubSubClass

Continuous and nonuniform or irregular surface on layer or...

Other Related Categories

428212, 428336, 428694T, 428694TR, 428694TM, 428694TS, 428900, 427128, 427132, 427533, 360134, 360136, G11B 566, B32B 702, B32B 310

Type

Patent

Status

active

Patent number

055253989

Description

ABSTRACT:
A perpendicular magnetic recording medium has a magnetic layer comprised of two stacked sublayers each in the form of ferromagnetic metal thin film consisting of columnar crystal grains wherein the angle .theta. between the average growth direction of the columnar crystal grains and a normal to the substrate is .theta..gtoreq.45.degree. for the lower sublayer and .theta..ltoreq.30.degree. for the upper sublayer, and the mean maximum diameter of columnar crystal grains of the lower sublayer is not smaller than the mean maximum diameter of columnar crystal grains of the upper sublayer. An apparatus suitable for the evaporation of the magnetic layer is arranged as shown in the Figure. Magnetic flux associated with the upper sublayer finds an escape to the lower sublayer, preventing formation of a closed loop of magnetic flux within the columnar crystal grains of the upper sublayer. The lower sublayer is magnetized, thus contributing to an improvement in reproduction output.

REFERENCES:
patent: 4387136 (1983-06-01), Saito et al.
patent: 4511635 (1985-04-01), Nagao et al.
patent: 4521481 (1985-06-01), Nagao et al.
patent: 4536443 (1985-08-01), Nagao et al.
patent: 4596735 (1986-06-01), Noguchi et al.
patent: 4622271 (1986-11-01), Arai et al.
patent: 4770924 (1988-09-01), Takai et al.
patent: 4900622 (1990-02-01), Nakayama et al.
patent: 4999220 (1991-03-01), Honda et al.
patent: 5000995 (1991-03-01), Kishi et al.
patent: 5073449 (1991-12-01), Niimi et al.

Affiliated with

Also associated with

Rating

Perpendicular magnetic recording medium and method for making does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Perpendicular magnetic recording medium and method for making, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Perpendicular magnetic recording medium and method for making will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-350540