Patents by Inventor Katsuhiko Koi
Katsuhiko Koi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 8259419Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: GrantFiled: September 23, 2011Date of Patent: September 4, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20120009440Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: ApplicationFiled: September 23, 2011Publication date: January 12, 2012Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideaki FUKUZAWA, Katsuhiko KOI, Hiromi FUKE, Hiroshi TOMITA, Hitoshi IWASAKI, Masashi SAHASHI
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Patent number: 8049999Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: GrantFiled: December 31, 2008Date of Patent: November 1, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20090109581Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: ApplicationFiled: December 31, 2008Publication date: April 30, 2009Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideaki FUKUZAWA, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 7476414Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: GrantFiled: December 2, 2004Date of Patent: January 13, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 7130163Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: GrantFiled: October 6, 2004Date of Patent: October 31, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20050094322Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: ApplicationFiled: December 2, 2004Publication date: May 5, 2005Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20050047028Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: ApplicationFiled: October 6, 2004Publication date: March 3, 2005Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 6853520Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: GrantFiled: September 4, 2001Date of Patent: February 8, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Patent number: 6816347Abstract: A first layer region of a magnetically pinned layer in a spin valve structure, which is relatively remoter from a non-magnetic intermediate layer, is made of a ferromagnetic material containing at least one element selected from the group consisting of Cr (chrome), Rh (rhodium), Os (osmium), Re (rhenium), Si (silicon), Al (aluminum), Be (beryllium), Ga (gallium), Ge (germanium), Te (tellurium), B (boron), V (vanadium), Ru (ruthenium), Ir (iridium), W (tungsten), Mo (molybdenum), Au (gold), Pt (platinum), Ag (silver) and Cu (copper). Thereby, it is possible to provide a structure of the magnetically pinned layer, which can be readily made using a conventional deposition method and can ensure a sufficient electron reflecting effect on the part of the magnetically pinned layer, and to provide a magnetoresistive element using a spin valve film including the particular structure.Type: GrantFiled: December 28, 2000Date of Patent: November 9, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Katsuhiko Koi, Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Hideaki Fukuzawa
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Patent number: 6754053Abstract: A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.Type: GrantFiled: March 29, 2002Date of Patent: June 22, 2004Assignee: Kabushiki Kaisha ToshibaInventors: Masatoshi Yoshikawa, Masashi Sahashi, Katsuhiko Koi, Hitoshi Iwasaki, Hiromi Yuasa, Hideaki Fukuzawa
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Publication number: 20020191354Abstract: A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.Type: ApplicationFiled: March 29, 2002Publication date: December 19, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Masatoshi Yoshikawa, Masashi Sahashi, Katsuhiko Koi, Hitoshi Iwasaki, Hiromi Yuasa, Hideaki Fukuzawa
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Publication number: 20020048127Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.Type: ApplicationFiled: September 4, 2001Publication date: April 25, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Hideaki Fukuzawa, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
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Publication number: 20010013999Abstract: A first layer region of a magnetically pinned layer in a spin valve structure, which is relatively remoter from a non-magnetic intermediate layer, is made of a ferromagnetic material containing at least one element selected from the group consisting of Cr (chrome), Rh (rhodium), Os (osmium), Re (rhenium), Si (silicon), Al (aluminum), Be (beryllium), Ga (gallium), Ge (germanium), Te (tellurium), B (boron), V (vanadium), Ru (ruthenium), Ir (iridium), W (tungsten), Mo (molybdenum), Au (gold), Pt (platinum), Ag (silver) and Cu (copper). Thereby, it is possible to provide a structure of the magnetically pinned layer, which can be readily made using a conventional deposition method and can ensure a sufficient electron reflecting effect on the part of the magnetically pinned layer, and to provide a magnetoresistive element using a spin valve film including the particular structure.Type: ApplicationFiled: December 28, 2000Publication date: August 16, 2001Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Katsuhiko Koi, Hitoshi Iwasaki, Yuzo Kamiguchi, Hiromi Fuke, Hideaki Fukuzawa