Hitachi, Ltd.

Katsuhiro Kaneko

Yutaka Sugita

Toshio Niihara

Shinji Takayama

Nagatugu Koiso

Hiroshi Umezaki

Hirozi Yamada

Hideki Nishida

Kazuetsu Yoshida

Norikazu Tsumita

Keiichi Kanehori

Michiharu Seki

Yo Sakurai

Masatake Takahashi, Deceased

A magneto-optical recording medium made of a rare-earth-transition metal amorphous film provides a compensation temperature Tcomp of 50.degree.-200.degree. C. or 0.degree. C. or less. This compensation temperature decreases a saturation magnetization Ms during recording, thereby preventing the provision of inverted magnetic domains at the centers of recording domains resulting from the demagnetizing field generated by the strength distribution of laser light, and so improving a carrier-to-noise ratio during reading. In the case of using a Tb-Fe-Co system amorphous film, Tcomp of 50.degree.-200.degree. C. may be give by the composition comprising Tb of 24-30 atomic %, Co of 7-20 atomic % and Fe of the rest, and Tcomp of 0.degree. C. or less may be given by the composition comprising Tb of 18-21.5 atomic %, Co of 8-10 atomic % and Fe of the rest.

Magneto-optical recording medium

Disclosed is a magneto-optical recording material whose composition formula is indicated by (Co.sub.1-a M.sub.a).sub.100-y R.sub.y where M denotes at least one element selected from the group consisting of elements of the platinum group and Fe, Ni, Nb, Cu, Ag, Al, B, Si and Ge; R denotes either at least two elements selected from the group consisting of Tb, Sm, Gd, Dy, Ho and Y or a single element selected from the group consisting of Tb, Gd, Dy and Ho; the value a satisfies 0&lt;a.ltoreq.0.5, while the value y satisfies 14.ltoreq.y.ltoreq.36 in terms of atomic percent; the material being substantially amorphous. A perpendicularly magnetized amorphous film made of this material is excellent in thermal stability, corrosion resistance etc., and affords a greater read output-to-noise ratio (C/N).

Magneto-optical recording material

A method of forming a microscopic pattern wherein the object to be etched is overlaid with a film made of a material which is highly immune to etching and further provided with a reflection reducing film. Thus, the reflection of the irradiating ultraviolet rays by the underlying layer is effectively prevented.

Method of forming a microscopic pattern

A magnetic bubble memory device is disclosed in which a hardened film made of a heat-resisting highly-polymerized organic resin and having a predetermined thickness is employed for an insulating film interposed between a conductor pattern and a soft magnetic material pattern. In a conventional magnetic bubble memory device in which the above-mentioned insulating film is made of SiO.sub.2, an abrupt step is produced in the soft magnetic material pattern due to the existence of the conductor pattern beneath a portion of the soft magnetic material pattern, and the margin of bias magnetic field is thereby lowered. According to the present invention, the step is reduced and smoothed, and thus the lowering of the margin can be prevented.

Magnetic bubble memory device

A catalyst comprising carbonaceous materials such as activated carbon, etc. impregnated with bromine, iodine, chlorine or their compounds, is impregnated with a promoter containing a specific metal, and brought in contact with a flue gas in the presence of ammonia, whereby nitrogen oxides and sulfur oxides contained in the flue gas are removed with a very high percent removal. The removal can be carried out at a temperature much lower than that of the conventional process.

Process for removing sulfur oxides and nitrogen oxides from flue gases

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Sayama, Japan

Katsuhiro Kaneko