Hitachi, Ltd.

International Business Machines Corporation

Hitachi Metals, Ltd.

Hitachi Research Dev. Corp.

Shinji Takayama

Mitsuhiro Kudo

Shigekazu Otomo

Yutaka Sugita

Noriyuki Kumasaka

Hideo Fujiwara

Takeo Yamashita

Noritoshi Saito

Teruhisa Shimizu

Yukio Okamoto

Kazumasa Takagi

Toshiyuki Aida

Toshio Niihara

Tokuumi Fukazawa

Yasunobu Ogata

Katsuki Miyauchi

Katsuhiro Kaneko

Yoshizo Sawada

Hiroshi Tanaka

Philip Louis Trouilloud

Fumiyoshi Kirino

Kazuo Shiiki

Anthony Paul Praino

Mark E Re

Bernell E Argyle

Yoshimine Kato

Yasuo Tsukuda

Nobuo Kobayashi

Hideo Iiyori

Yoshihiro Ikeda

Rudolf Schafer

A conductor line material is provided which has an extremely low electric resistance such as 10 .mu..OMEGA..multidot.cm or less, and in preferred embodiments, about 5 .mu..OMEGA..multidot.cm, which causes no defect such as hillocks and pinholes even at high temperatures, and which easily forms strong insulation films by anodic oxidation. An Al-based conductor line material comprising an alloy whose composition formula is substantially expressed by Al.sub.x (M.sub.y N.sub.1-y).sub.1-x, where M represents at least one element selected from a group consisting of rare-earth elements, N represents at least one element selected from a group consisting of Nb, Zr and Ta, x is between 98 and 99.5 atomic percent, and y is a number between 0.1 and 0.9, wherein an intermetallic compound of Al with said element represented by M or N is deposited in the matrix by subsequent heat treatment. The same object may be achieved by an alloy of Al to which 0.5-2.0 atomic percent Nb is added. The temperature of heat treatment in both cases is preferably in a range between 250 and 450.degree. C.

Conductor line materials and method of making their metal line layers

The invention is intended to provide a magnetic recording medium suitable for longitudinal recording, which has low medium noise and high coercivity. A magnetic recording medium includes a substrate 1 and a magnetic layer 2 formed on the substrate 1. The magnetic layer 2 consists of a mixture of a magnetic alloy and a non-magnetic compound. The magnetic alloy is Co-based, Fe-based, or CoFe-based, and the non-magnetic compound is selected from a group consisting of oxides and nitrides. The volume percentage of the non-magnetic compound in the entire volume of the mixed magnetic alloy and non-magnetic compound is preferably not less than about 2% and not more than about 30%.

Magnetic recording medium and its fabrication method

Method for fabricating magnetic recording medium

A high permeability Fe-based alloy having a composition of (Fe.sub.a M.sub.100-a).sub.100-b X.sub.b, wherein M represents at least one element selected from a group consisting of Nb, Zr, Ta, Hf, Ti, V, and Si, and X represents hydrogen or oxygen. The letters a and b represent atomic percentages, wherein preferably 85&lt;=a&lt;=97 and 4&lt;=b&lt;=10. In the preferred embodiment, the alloy comprises a nano-scale alpha-Fe crystalline phase having a grain size of less than 20 nm.

High permeability iron-based alloy

A magnetic recording medium includes a successively formed uneven underlayer and magnetic layer. In the process of forming the underlayer, grains of an alloy, whose melting point is in the range of approximately 100 degrees centigrade to approximately 350 degrees centigrade, are deposited on a substrate by using either an evaporation or a sputtering method, while maintaining the substrate temperature at a temperature which allows molten spheres of the alloy to be formed. The preferred alloys include Zn, Mg, Al, In, and Sn systems whose melting points fall within the above-mentioned temperature range. The preferred substrate temperatures are not higher than the melting point of the alloy to be deposited plus 50 degrees centigrade, and most preferably, temperatures equal to approximately the melting point of the alloy to be deposited minus 20 degrees centigrade. The result is a magnetic recording medium suitable for practical use which can be fabricated at a low cost. In addition, in magnetic recording apparatus, the occurrence of adhesion between a magnetic recording medium and a transducer head is reduced.

Magnetic recording medium having an underlayer of low melting point

A method and apparatus for conditioning a magnetic read/write head to substantially eliminate read-back pulse distortions associated with unfavorable magnetic domain patterns in the head stores the polarity of the last write current pulse of a write pulse train applied to the head-coils. This polarity is compared to a pre-determined reset current pulse polarity. If the last write current polarity is opposite to the reset current polarity, then a reset pulse, or a series of pulses, having the pre-determined reset polarity is applied to the head prior to performing a read operation with the head. The pre-determined reset polarity corresponds to the polarity that resets the head to the magnetic domain state most preferred for reading due to reduction of read-back distortion. The reset pulse, or pulse train, according to the present invention is of constant polarity. If the last write current pulse polarity is the same as the reset polarity, then no reset pulse is applied to the head. Prior to applying the reset pulse, the head is either re-positioned or, if not re-positioned, the reset pulse is applied to the head only when it is flying over a sector gap.

Electrical means to diminish read-back signal waveform distortion in

Chemical reactions of superconducting raw materials with active oxygen atoms and their charged particles are accelerated by using at least oxygen plasma in the fabrication process of a superconductive body. Thereby an ionic crystal is grown in a short time, which provides stable superconducting materials of high quality such as high critical temperature and low resistivity. In another aspect, a substrate is irradiated simultaneously with streams of vapor of metal elements, of which a superconductive body is to be composed, and a stream of gas of ions generated in a plasma chamber and film growth is effected while keeping the substrate at a temperature higher than 400.degree. C. to produce a ceramic type superconductive thin film.

Method for fabricating superconducting materials and superconductive

A magneto-optical medium is comprised of three layers. The first layer is made of a rare earth-transition metal amorphous film from one to twenty nanometers thick. The second layer is comprised of a rear earth-transition metal amorphous film or crystalline film and is one to twenty nanometers thick. The third layer is comprised of a rare earth-transition metal amorphous film and is not less than two nanometers thick. The resulting medium has a sufficiently large magneto-optical effect even at short wave lengths and is perpendicular magnetized film. A data storage system including the magneto-optical medium therein.

Magneto-optical recording medium and system for use with short

A method and an apparatus for MO recording that allow real overwrite by light power modulation with a combination of a storage medium consisting of a single-layer RE-TM film and a single-laser source. The medium has a Curie temperature not less than about 500.degree. C. and has high saturation magnetization around 200.degree. C. The coercive force drops to a level that allows the magnetization to be reversed by the demagnetization field at around 200.degree. C.

Method and apparatus for magneto-optical recording using a

A first and a second magnetic layer are deposited on a substrate. The first magnetic layer has high magneto-optical effect at short wavelengths, but low perpendicular anisotropy. The second magnetic layer has low magneto-optical effect at short wavelengths, but high perpendicular anisotropy. The magnetic exchange coupling between the two magnetic layers results in a recording medium which has strong perpendicular anisotropy and high magneto-optical effect, even at short wavelengths.

Magneto-optical recording medium

An amorphous magnetic alloy of Co-Nb-Zr system contains Co, Nb and Zr and has a composition which falls, in terms of atomic percent, within the region defined by straight lines connecting, in a ternary composition diagram assuming the total of contents of these three elements to be 100, a point (81% Co, 14% Nb, 5 Zr), a point (88% Co, 9% Nb, 3% Zr), a point (86.5% Co, 12.5% Nb, 1% Zr) and a point (81% Co, 18% Nb, 1% Zr). Disclosed also is a magnetic head having a core at least a part of which is constituted by this amorphous magnetic alloy. This magnetic head, when used in combination with a metal powder tape having a high coercive force, provides a remarkably increased recording-reproducing output.

Amorphous magnetic alloy of Co-Nb-Zr system and magnetic head made from

A process for fabricating a superconducting oxide thin film is disclosed which comprises the steps of separately evaporating metal elements, of which the superconducting oxide thin film with a desired stoichiometry is to be composed, to a substrate and simultaneously irradiating the substrate with oxygen plasma generated by RF wave or ECR microwave to form a crystalline oxide film without further annealing.

Method for fabricating superconducting oxide thin films by activated

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.

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 magneto-optical recording medium comprising a perpendicularly magnetized amorphous film made of an alloy of the formula: (R.sub.1-x M.sub.x).sub.a (Fe.sub.1-y Co.sub.y).sub.100-a, wherein R is at least one of La, Ce, Pr, Nd, Sm, Ho, Er and Yb; M is at least one of Tb, Gd and Dy; 0.ltoreq.x&lt;0.5; 0&lt;y&lt;1; and 10.ltoreq.a.ltoreq.40, is large in the Kerr rotation angle, excellent in coercivity and affords a larger read output-to-noise ratio (C/N).

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Mitaka, Japan

Shinji Takayama