The influence of the pregroove on the shape of thermomagnetically written domains

Journal Article · Tue May 15 00:00:00 EDT 1990 · Journal of Applied Physics; (USA)

DOI:https://doi.org/10.1063/1.345134· OSTI ID:6986424

Ichihara, K ^[1]

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1. Toshiba Corporation, R D Center, 1 Komukai-Toshiba-cho, Saiwai-ku, Kawasaki, Kanagawa 210, Japan (JP)

In order to clarify the influence of pregrooved substrates on the shape of thermomagnetically written domains, the difference between the shape of the domains written on a pregrooved area and that written on a mirror area have been examined. Trilayered magneto-optical media, which had rare-earth- (RE-) rich TbFeCo films, transition-metal-rich TbFeCo films, and RE-rich GdTbFeCo films as a recording layer, were sputtered on disk substrates. The substrates had both a pregrooved area and a mirror area in a recording track. The domains were written in each medium by varying the recording power and the external field, and were observed by an Ar{sup +} -laser scanning polarized microscope. In the case of TbFeCo media which were written with lower recording power condition, the shape of the domains on a pregrooved area were almost the same as those written on a mirror area. On the other hand, the widths of the domains written on a mirror area became larger than those of domains written on a pregrooved area when the recording power was increased. In the case of a GdTbFeCo medium, the widths of the domains written on a mirror area were much larger than those of domains written on a pregrooved area independent of the recording conditions. The lengths of the domains written on both areas were almost the same for all cases. It is believed that the reason for the experimental results is that thermal diffusion in the film plane is suppressed at the step of a pregroove. The different result between TbFeCo and GdTbFeCo films is believed to come from the differences in the contracting forces on the domain walls during the writing process.

• OSTI ID: 6986424
• Journal Information: Journal of Applied Physics; (USA), Journal Name: Journal of Applied Physics; (USA) Vol. 67:10; ISSN 0021-8979; ISSN JAPIA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
ALLOYS
COBALT ALLOYS
DIFFUSION
DOMAIN STRUCTURE
ELECTROMAGNETIC RADIATION
FILMS
IRON ALLOYS
LASER RADIATION
MAGNETIC STORAGE DEVICES
MAGNETISM
MAGNETO-OPTICAL EFFECTS
MEMORY DEVICES
MICROSCOPY
RADIATIONS
RARE EARTH ALLOYS
SPUTTERING
TERBIUM ALLOYS
THERMAL DIFFUSION
THERMOMAGNETISM