Patents by Inventor Junnichi NAGAOKA
Junnichi NAGAOKA 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: 11810699Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.Type: GrantFiled: December 22, 2017Date of Patent: November 7, 2023Assignee: TDK CorporationInventors: Junnichi Nagaoka, Hitoshi Taguchi, Yuichi Sugawara, Jo Sato
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Publication number: 20230290547Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.Type: ApplicationFiled: May 19, 2023Publication date: September 14, 2023Applicant: TDK CorporationInventors: Junnichi NAGAOKA, Hitoshi TAGUCHI, Yuichi SUGAWARA, Jo SATO
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Patent number: 11569013Abstract: This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A1-xRx(Fe12-yMey)z, the Fe2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.Type: GrantFiled: May 19, 2017Date of Patent: January 31, 2023Assignee: TDK CORPORATIONInventors: Junnichi Nagaoka, Hitoshi Taguchi
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Patent number: 11450458Abstract: Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.Type: GrantFiled: February 22, 2019Date of Patent: September 20, 2022Assignee: TDK CorporationInventors: Junnichi Nagaoka, Hiroyuki Ono, Yuichi Sugawara
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Patent number: 11417447Abstract: This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A1-xRx(Fe12-yMey)z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.Type: GrantFiled: May 19, 2017Date of Patent: August 16, 2022Assignee: TDK CORPORATIONInventors: Junnichi Nagaoka, Hitoshi Taguchi
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Patent number: 11205533Abstract: A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.Type: GrantFiled: February 22, 2019Date of Patent: December 21, 2021Assignee: TDK CorporationInventors: Junnichi Nagaoka, Hiroyuki Ono, Yuichi Sugawara
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Publication number: 20190318856Abstract: Provided is a ferrite sintered magnet including a ferrite phase having a magnetoplumbite-type crystal structure. x, y, and m satisfy the following Equations (1), (2), and (3) when composition of the ferrite sintered magnet is represented by R1-xAxFem-yCoy, where R denotes at least one kind of element selected from rare earth elements including Y and A denotes Ca or Ca and elements including at least one kind selected from Sr or Ba. The content of B in the ferrite sintered magnet is from 0.1% to 0.6% by mass in terms of B2O3. 0.2?x?0.8??(1) 0.1?y?0.Type: ApplicationFiled: December 22, 2017Publication date: October 17, 2019Applicant: TDK CorporationInventors: Junnichi NAGAOKA, Hitoshi TAGUCHI, Yuichi SUGAWARA, Jo SATO
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Publication number: 20190267168Abstract: Provided is a ferrite sintered magnet including a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure, in which the main phase contains Fe and Co, and the ferrite sintered magnet contains CaB2O4. CaB2O4 is contained in a heterophase that is a crystalline phase different from the main phase, and an area ratio of CaB2O4 to the entire cross-sectional surface of a sintered magnet, is less than or equal to 2%.Type: ApplicationFiled: March 29, 2019Publication date: August 29, 2019Applicant: TDK CorporationInventors: Junnichi NAGAOKA, Hiroyuki ONO, Yuichi SUGAWARA
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Publication number: 20190267167Abstract: A ferrite sintered magnet contains a main phase formed of ferrite having a hexagonal magnetoplumbite type crystalline structure; a first subphase containing La, Ca, and Fe, in which an atomic ratio of La is higher than that of the main phase, and the atomic ratio of La is higher than an atomic ratio of Ca; and a second subphase containing La, Ca, Si, B, and Fe, in which an atomic ratio of Ca is higher than an atomic ratio of La, an atomic ratio of B is higher than an atomic ratio of Fe, and the atomic ratio of Fe is lower than that of the main phase. An area ratio of the second subphase on a cross-sectional surface of the ferrite sintered magnet is greater than or equal to 1%.Type: ApplicationFiled: February 22, 2019Publication date: August 29, 2019Applicant: TDK CorporationInventors: Junnichi NAGAOKA, Hiroyuki ONO, Yuichi SUGAWARA
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Publication number: 20190206594Abstract: This ferrite magnet has a ferrite phase having a magnetoplumbite structure, and an orthoferrite phase, and is characterized in that the composition ratios of the total of each metal element A, R, Fe and Me is represented by expression (1) A1-xRx(Fe12-yMey)z, (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn) and in that the content (m) of the orthoferrite phase is 0<m<28.0 in mol %. The invention makes it possible to achieve a ferrite magnet with increased Br.Type: ApplicationFiled: May 19, 2017Publication date: July 4, 2019Applicant: TDK CORPORATIONInventors: Junnichi NAGAOKA, Hitoshi TAGUCHI
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Publication number: 20190122792Abstract: This ferrite magnet has a magnetoplumbite structure and is characterized in that, when representing the composition ratios of the total of each metal element A, R, Fe and Me with expression (1) A1-xRx(Fe12-yMey)z, the Fe2+ content (m) in the ferrite magnet is greater than 0.1 mass % and less than 5.4 mass % (in expression (1), A is at least one element selected from Sr, Ba, Ca and Pb; R is at least one element selected from the rare-earth elements (including Y) and Bi, and includes at least La, and Me is Co, or Co and Zn). The invention makes it possible to achieve a ferrite magnet with increased Br.Type: ApplicationFiled: May 19, 2017Publication date: April 25, 2019Applicant: TDK CORPORATIONInventors: Junnichi NAGAOKA, Hitoshi TAGUCHI