| Project/Area Number |
03680050
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
結晶学
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| Research Institution | Teikyo University, School of Science and Engineering |
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Principal Investigator |
OHBA Takuya Teikyo University, School of Science and Engineering, Associate Professor, 理工学部, 助教授 (00211110)
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| Co-Investigator(Kenkyū-buntansha) |
HARA Toru Teikyo University, School of Science and Engineering, Research Assistant, 理工学部, 助手 (70238161)
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| Project Period (FY) |
1991 – 1992
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| Project Status |
Completed (Fiscal Year 1992)
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| Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1992: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Nd-Fe-B / composite crystal / incommensurate / NdーFeーB |
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| Research Abstract |
Nd-Fe-B, B-rich phase is a composite crystal which is constructed by two subsystems interpenetrating each other, i.e. Nd and Fe subsystems. Small crystals of this phase were chosen and X-ray diffraction intensities along the c axis were measured by four circle diffractometer. Relationship between the period of the structure and heat treatment was investigated. It is difficult to find the correlation between the effect of heat treatment and the period of the structure. Lattice constants of this phase were reported by several authors and they are not consistent each other, especially in c axis. In order to resolve the inconsistency, the period, c, for many samples were investigated and it is found that the period of the structure is determined by a difference of the period of Nd and Fe subsystems. The period of Nd subsystem can be easily modified but that of Fe cannot be easily modified. That is the reason why there are several reports about lattice constants. Crystal structure was investigated by some authors based on an assumption of commensurate structure. However, most of the crystal of this phase is incommensurate. For the structural study, interference effect between two subsystems, which should be considered but has not been made, was considered by using a Bessel function. Interesting results were derived through the consideration and a basic understanding of the crystal structure of the composite crystal has been revealed by this study. Precise measurements of diffraction profiles along the c axis were made with Nd and Fe absorption edges by synchrotrons radiation at Photon Factory in KEK. The periods of modulation of Nd and Fe subsystems are slightly different. It is first time to observe the contribution of Nd and Fe subsystems separately.
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