Hitachi, Ltd.

Shun-ichi Narumi

Moriaki Fuyama

Hiroshi Fukui

Hisashi Takano

Takashi Kawabe

Masaaki Sano

Kenzo Masuda

Yoshiaki Kita

Hisano Yamamoto

Kazue Kudo

Katsumi Hoshino

Katsuo Watanabe

Matahiro Komuro

A magnetic disk apparatus includes a magnetic disk for recording information and a magnetic head which has a reproducing head and a recording head. The reproducing head comprising a lower shield film, a magnetoresistive film, a pair of electrodes and an upper shield, and the recording head comprising an upper magnetic core, a lower magnetic core, and a coil disposed between said upper magnetic core and said lower magnetic core. The upper magnetic core and the lower magnetic core include an electroplated thin film with an average crystal grain size smaller than 500 &angst;, and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Magnetic disk apparatus with magnetic head having upper and lower magnetic cores of an electroplated thin film

A magnetoresistive effect type reproducing head includes a lower magnetic shield made of magnetic material, an upper magnetic shield made of magnetic material, a magnetoresistive effect type element formed between the lower magnetic shield layer and the upper magnetic shield layer, a lower inter-layer insulating film formed between the magnetoresistive effect type element and the lower magnetic shield, and an upper inter-layer insulation film formed between the magnetoresistive effect type element and the upper magnetic shield. At least one of the lower and upper magnetic shields includes a first magnetic layer made of a first material having first electric resistivity and a second magnetic layer made of a second material having second electric resistivity higher than the first electric resistivity.

Magnetoresistive effect type reproducing head and magnetic disk apparatus equipped with the reproducing head

An inductive thin-film magnetic head with small fluctuations of the reproduction output and noises for reproduction is disclosed. The forward end of each of a lower magnetic core and an upper magnetic core has the same width as the track. The rear end of each of the lower magnetic core and the upper magnetic core, on the other hand, is wider than the forward end thereof in the direction transverse of the track. Also, the lower magnetic core is formed of at least two magnetic layers with a non-magnetic layer interposed therebetween.

Thin film magnetic head including a protrusion structure and an insulation film in a magnetic core

Magnetic head including an inductive magnetic head having a lower magnetic core of a magnetic film/non-magnetic film/magnetic film multilayer structure

A slider having a thin film magnetic head. The thin film magnetic head has an upper magnetic core, a lower magnetic core and a coil disposed between the upper magnetic core and the lower magnetic core. The upper magnetic core and the lower magnetic core is an electroplated thin film with an average crystal grain size smaller than 500 &angst;, and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Thin film magnetic head with electroplated Ni-Fe alloy thin film having small average crystal grain size range

A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein a resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;&middot;cm.

A thin film magnetic head having a first magnetic core, a second magnetic core formed on the first magnetic core, a coil disposed between the first magnetic core and second magnetic core, and a non-magnetic insulator body for separating the first magnetic core, second magnetic core and coil with respect to each other. At least one of the first magnetic core and the second magnetic core includes an electroplated thin film with an average crystal grain size smaller than 500 &angst; and the electroplated thin film is made of Ni&mdash;Fe alloy of which Ni is 38 to 60 wt % and Fe is 40 to 62 wt %.

Thin film magnetic head and assembled construction thereof

A magnetoresistive effect type reproducing head is formed by stacking a lower magnetic shield made of magnetic material, a lower inter-layer insulation film, a magnetoresistive effect type element for detecting a magnetic field by using a magnetoresistive effect, an upper inter-layer insulation film, and an upper magnetic shield made of magnetic material, on a substrate in this order, wherein the resistivity of at least one of the lower and upper magnetic shields is more than 200 &mgr;&OHgr;&middot;cm.

An inductive thin-film magnetic head with small flucuations of the reproduction output and noises for reproduction is disclosed. The forward end of each of a lower an upper magnetic and an upper magnetic core has the same width as the track. The rear end of each of the lower magnetic core and the upper magnetic core, on the other hand, is wider than the forward end thereof in the direction of the track. Also, the lower magnetic core is formed of at least two magnetic layers with a non-magnetic layer interposed therebetween.

Dual-element thin-film magnetic head including a composite lower core

A thin film magnetic head and a disk storage system having a magnetic disk and the thin film magnetic head provided on a floating type slider. The thin film magnetic head has an upper magnetic core and a lower magnetic core, wherein the upper magnetic core and the lower magnetic core are made of an electroplated thin film having sufficient average crystal grain size. The upper magnetic core is made of a Ni&mdash;Fe alloy having Ni of 38 to 60 wt % and Fe of 40 to 62 wt %, and the crystal grain size is smaller than 500 &angst;.

Thin film magnetic head with Ni-Fe alloy thin film

A magnetic film having a high saturation magnetic flux density larger than 1.5 T and a resistivity larger than 40 .mu..OMEGA..cndot.cm is fabricated through an electroplating method using (40-60)Ni-Fe and by adding Co, Mo, Cr, B, In, Pd or the like to the (40-60)Ni-Fe. Thereby, it is possible to obtain a recording head capable of performing sufficient recording in a high frequency range and to obtain a disk storage system with a high recording density which has a transfer rate higher than 15 MB/s, a recording frequency higher than 45 MHz and a rotating speed of a magnetic disk higher than 4000 rpm.

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Hitachi, Japan

Shun-ichi Narumi