Sanyo Electric Co., Ltd.

Kazuo Ino

Takashi Ogura

Hiroyuki Okuda

Yoshiaki Shimizu

Kousou Ishihara

Jyoichi Tamada

Isao Tanaka

Fumio Kameoka

Koso Ishihara

Takao Yamano

Kouzo Ishihara

Tsukasa Shimizu

Horiyuki Okuda

Masaru Doi

A magnetic head comprises a pair of magnetic core halves, heat-resistant thin films and ferromagnetic thin films, the pair of magnetic core halves being opposed to each other through a non-magnetic material such as SiO.sub.2 to form a magnetic gap. The magnetic core halves are made of a ferromagnetic oxide such as ferrite and have gap forming faces to be opposed to each other to form the magnetic gap. The gap forming faces are etched by phosphoric acid solution and then purified by reverse sputtering, so that a grown crystal of the ferromagnetic oxide is exposed on the gap forming faces. A heat-resistant thin film of a heat-resistant material such as SiO.sub.2 is formed on each of the gap forming faces. A ferromagnetic thin film of a ferromagnetic metal material such as sendust is formed on each heat-resistant thin film. Preferably, the thickness of the heat-resistant thin film to be formed is 1 nm or more and one tenth or less of the width of the magnetic gap. For example, SiO.sub.2 films of 5 nm in thickness as the heat-resistant thin films are formed on the respective gap forming faces and sendust films of 3 .mu.m in thickness as the ferromagnetic metal thin films are formed on the respective SiO.sub.2 films. In this case, the gap length of the magnetic gap is set to 0.2 .mu.m.

Magnetic head with suppressed generation of pseudogap

A parallel type MIG (Metal in Gap) magnetic head includes single-crystal ferrite core halves with a thin ferromagnetic film formed on the gap-forming face of at least one of the core halves. The core halves are joined together using a glass having an Fe content in the range of 2-13 at %. The crystalline geometry of the principal magnetic path forming faces and gap forming faces of the core halves is selected to minimize the pseudo-gap problem and to improve reproduction output.

MIG magnetic head structured to minimize pseudo-gap problem

With a view to solving the problem of 'pseudo-gap' in a parallel type MIG head and to improving its reproduction output, effective combinations of the principal magnetic path forming face and the gap-forming face were determined empirically for the case of using a single-crystal ferrite core material. The improved magnetic head comprises a pair of magnetic core halves made of a single-crystal ferrite, at least one of said magnetic core halves having a thin ferromagnetic metal film formed on the gap-forming face, and said thin ferromagnetic metal film abutting against the other magnetic core half with a non-magnetic material being interposed to form a magnetic gap, the improvement wherein the principal magnetic path forming face of the magnetic core half provided with said thin ferromagnetic metal film has a crystal plane generally designated {211} whereas a vector A that is parallel to the &lt;110&gt; crystal axis in said principal magnetic path forming face and that is directed away from the gap-forming face forms an angle .theta. of the range 0.degree.-60.degree. or 150.degree.-180.degree. with a vector B that is parallel to the intersection of the principal magnetic path forming face and the gap-forming face and that approaches the face opposite to a recording medium.

Magnetic head having a single-crystal ferrite core

Method of manufacturing a magnetic core half

A magnetic head has a pair of magnetic core halves opposed to each other with a non-magnetic material posed therebetween to form a magnetic gap, which head includes a pair of magnetic core halves, a first ferromagnetic metal thin film and a second ferromagnetic metal thin film. The magnetic core halves are formed of ferromagnetic oxide such as Mn-Zn ferrite, and they have opposing surfaces opposed to each other to provide the magnetic gap. The first ferromagnetic metal thin film formed of Fe-Si-Al alloy is formed at least on one of the opposing surfaces. The second ferromagnetic metal thin film formed of Fe-Si-Al alloy having different constituent ratio from the first ferromagnetic metal thin film is formed between the magnetic gap and the first ferromagnetic metal thin film. The flux density of the second ferromagnetic metal thin film induced when a magnetic field of 1.2K oersted is applied exceeds 1000 gauss. The ratio of the saturation flux density of the second ferromagnetic metal thin film to that of the first ferromagnetic metal thin film is not higher than 0.6. The self recording reproducing capability of the magnetic head is not degraded in the high frequency region, and the self recording reproducing capability in the low frequency region is increased.

Magnetic head with improved efficiency in both high and low frequency

A magnetic head comprises a pair of magnetic core halves (1a, 1b), which are abutted with each other through a nonmagnetic material to define a magnetic gap (2), and ferromagnetic thin films (3a, 3b). The magnetic core halves (1a, 1b), which are formed of ferromagnetic oxide, have gap forming surfaces to be abutted with each other. The ferromagnetic metal thin films (3a, 3b) are selectively formed on the gap forming surfaces of the pair of magnetic core halves (1a, 1b). A ferromagnetic thin film (3b) is so formed that portion (12b, 12c, 12d) to be provided with a track width regulating groove (13b), a coil groove (13c) or a joining member receiving groove (13d) is exposed within a gap forming surface of one magnetic core half member (7b). Another ferromagnetic thin film (3a) is so formed that, in a gap forming surface of another magnetic core half member (7a), a portion (12e, 12f) opposite to the coil groove (13c) or the joining member receiving groove (13d) to be provided in the gap forming surface of the magnetic core half member (7b) is exposed. These ferromagnetic thin films (3a, 3b) are selectively formed by ion beam etching. Grooves (13b, 13c, 13d) are provided in one magnetic core half (1b) by mechanical working through a dicing saw or the like.

Magnetic head and method of manufacturing the same

A magnetic head comprises a pair of magnetic core halves (1a, 1b), which are abutted with each other through a nonmagnetic material to define a magnetic gap (2), and ferromagnetic thin films (3a, 3b). The magnetic core halves (1a, 1b), which are formed of ferromagnetic oxide, have gap forming surfaces to be abutted with each other. The ferromagnetic metal thin films (3a, 3b) are selectively formed on the gap forming surfaces of the pair of magnetic core halves (1a, 1b). A ferromagnetic thin film (3b) is so formed that portion (12b, 12c, 12d) to be provided with a track width regulating groove (13b), a coil groove (13c) or a joining member receiving groove (13d) is exposed within a gap forming surface of one magnetic core half member (7b). Another ferromagnetic thin film (3a) is so formed that, in a gap forming surface of another magnetic core half member (7a), a portion (12e, 12f) opposite to the coil groove (13c) or the joining member receiving groove (13d) to be provided in the gap forming surface of the magnetic core half member (7b) is exposed. These ferromagnetic thin films (3a, 3b) are selectively formed by ion means beam etching. Grooves (13b, 13c, 13d) are provided in one magnetic core half (1b) by mechanical working through a dicing saw or the like.

Method of manufacturing magnetic heads

Metal-in-gap head with heat resistant layers

A magnetic recording apparatus of a helical scanning system comprises a rotary cylinder (13), recording heads (A and B) and an erase head (10) attached to slightly project from a rotating surface (13a) of the cylinder (13). The rotary erase head (10) has a gap (4) comprising a ferrite core half (1) and a Sendust film (3) formed on a ferrite core half (2) opposed to the ferrite core half (1) and having a larger saturation magnetic flux density. In addition, the recording heads (A and B) and the rotary erase head (10) are attached on the rotary cylinder (13) so that an end (P1) located forward with respect to the tape travelling direction (11) of the Sendust film (3) may trace the backward side with respect to the tape travelling direction (11), apart by a distance which is a half of the gap length of the rotary erase head (10), as compared with a forward end (Q) of a recorded track pattern ( 15a) formed on a tape (14) by the recording head (A) scanning immediately after erasing by the rotary erase head (10).

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Matsubara, Japan

Kazuo Ino