1996 Fiscal Year Final Research Report Summary
Microstructure and Magnetic Properties of SrOnFe_2O_3 (0.5<n<6.0)
| Project/Area Number |
06452322
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Structural/Functional materials
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| Research Institution | Tohoku University |
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Principal Investigator |
HOMMA Motofumi Faculty of Engineering, Tohoku University, Professor, 工学部, 教授 (50005261)
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| Co-Investigator(Kenkyū-buntansha) |
KAGOTANI Toshio Faculty of Engineering, Tohoku University, Research Associate, 工学部, 助手 (40005343)
SUGIMOTO Satoshi Faculty of Engineering, Tohoku University, Associate Professor, 工学部, 助教授 (10171175)
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| Project Period (FY) |
1994 – 1996
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| Keywords | ferrite magnet / SrO6Fe_2O_3 / 7SrO5Fe_2O_3 / BaO6Fe_2O_3 / BaOFe_2O_3 |
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| Research Abstract |
The low Fe_2O_3 content compound close to a SrO6 Fe_2O_3 in Sr-ferrite permanent magnets was identified, and the microstructures and magnetic propertis of the Sr-ferrites between them were studied.
1.The low Fe_2O_3 content compound close to a BaO6Fe_2O_3 (Ba-M) was a BaOFe_2O_3 (spinel) in BaO-Fe_2O_3system. However, it was a 7SrO5Fe_2O_3 compound (orthorhombic, "non-magnetic") in SrO-Fe_2O_3 system. The intensity of magnetization of Sr-ferrites decreased with decreasing Fe_2O_3 content.
2.The coercivity of the Sr-ferrites increased with decreasing Fe_2O_3 content, and marked a peak near the 7SrO5Fe_2O_3.
3.The Solubility of the 7SrO5Fe_2O_3 in the SrO6Fe_2O_3 (Sr-M) was about 2 mol Fe_2O_3% at an eutectic temperature (1470K), and decreased extremely with decreasing temperature, and disappeared below 1450K,while the solbulity of a BaOFe_2O_3 in a BaO6Fe_2O_3 was 2 mol Fe_2O_3% at room temperature.
4.It is excepted that new type ferrite permanent magnets having wall pinning induced by precipitation of non magnetic 7SrO 5Fe_2O_3 and BaO Fe_2O_3 particles in main magnetic conpounds (Ba/Sr-M) will be developed in SrO-BaO-Fe_2O_3 ternary system.
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