EP0039593A1
Expired / Lapsed
EP
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A method of producing a single crystal of ferrite
Assignee: NGK Insulators Ltd
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Filing: 1981-05-01
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Granted: —
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Expires: 2001-05-01
Abstract
Abstract A single crystal of ferrite is grown toward a polycrystal of ferrite by heating a polycrystal of ferrite and a single crystal seed of ferrite in contact with each other to effect a solid phase reaction. In this method, the polycrystal of ferrite utilized is prepared by using iron oxide containing iron oxide of spinel structure, iron oxide having hysteresis of spinel structure or mixture of these iron oxides in an amount of not less than 60% by weight calculated as Fe 2 O 3 , and the heating is effected at a temperature lower than the temperature at which discontinuous grain growth of the polycrystal of ferrite is caused.
Inventors
- 👤 Soichiro Matsuzawa
- 👤 Syunzo Mase
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 10:03
CPC Classifications
C; C30; C30B; C30B1/00; C30B1/02; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/26
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
107 words
A method of producing a single crystal of ferrite wherein a polycrystal of ferrite and a single crystal of ferrite are heated in contact with each other to grow the single crystal of ferrite toward the polycrystal of ferrite, characterized in that the polycrystal of ferrite is produced by using.iron oxide containing iron oxide of spinel structure and/or iron oxide having hysteresis of spinel structure in an amount of not less than 60% by'weight. calculated as Fe 2 0 31 and in that the said heating is effected at a temperature lower than the temperature at which discontinuous grain growth of the polycrystal of ferrite is caused.
Claim 2
Independent Claim
107 words
A method of producing a single crystal of ferrite wherein a polycrystal of ferrite and a single crystal of ferrite are heated in contact with each other to grow the single crystal of ferrite toward the polycrystal of ferrite, characterized in that the polycrystal of ferrite is produced by using.iron oxide containing iron oxide of spinel structure and/or iron oxide having hysteresis of spinel structure in an amount of not less than 60% by'weight. calculated as Fe 2 0 31 and in that the said heating is effected at a temperature lower than the temperature at which discontinuous grain growth of the polycrystal of ferrite is caused.
Claim 3
Dependent Claim
40 words
A method as claimed in Claim 1, characterized in that the iron oxide contains not less than 80% by weight calculated as Fe 2 0 3 of iron oxide of spinel structure and/or iron oxide having hysteresis of spinel structure.
Claim 4
Dependent Claim
29 words
A method as claimed in Claim 1 or 2, characterized in that impurities in the iron oxides comprise less than 0.02% by weight of SiO 2 and CaO, respectively.
References Cited (Backward Citations)
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