High Frequency Magnetic Losses in Soft Magnetic Materials
Project/Area Number |
62460119
|
Research Category |
Grant-in-Aid for General Scientific Research (B)
|
Allocation Type | Single-year Grants |
Research Field |
電子材料工学
|
Research Institution | Gifu University |
Principal Investigator |
SASAKI Tadashi Faculty of Engineering, Gifu University, 工学部, 教授 (70037901)
|
Co-Investigator(Kenkyū-buntansha) |
TAKADA Shunji Faculty of Engineering, Gifu University, 工学部, 助手 (30187968)
|
Project Period (FY) |
1987 – 1988
|
Project Status |
Completed (Fiscal Year 1988)
|
Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1988: ¥4,000,000 (Direct Cost: ¥4,000,000)
Fiscal Year 1987: ¥3,200,000 (Direct Cost: ¥3,200,000)
|
Keywords | High frequency magnetic loss / High frequency single sheet magnetic tester / Amorphous magnetic ribbon / 磁化速度 / 表面磁区構造 / 動的磁気ひずみ / 軟貭磁性材料の磁気損失 / 非正法波励磁による磁気損失 |
Research Abstract |
Loss measurements on soft magnetic materials magnetized at frequencies up to several MHz and high flux densities were made, and the physical origin of these high frequency magnetic losses was examined. A high frequency single sheet tester of amorphous magnetic ribbons was completed and magnetic properties at frequencies below 200 KHz have been able to be evaluated with this tester. At frequencies higher than 200 KHz, measurements in small rings allowed to justify the measured properties as well as in the other soft magnetic materials. From the results, the frequency dependence of hysteresis loss has been confirmed to exist. Most portions of the extremely low frequency loss in soft ferrites were analyzed to be an anomalous loss occuring from the thermal fluctuation after effect and the same loss mechanism has been observed in metallic soft magnetic materials. We found the interesting annealing process in amorphous ribbons in which, in spite of the degradation of permeability, the magnetic loss decreased with annealing time. It had been deduced that the annealing changed nature of magnetic domain walls. Further studies on these should be made in the future. Magnetization with a constant rate of magnetizing seed yielded lower losses than with the sinusoidal flux change. Loss separation was made about these losses and it has been known that magnetizing processes gradually changed with the frequency. By keeping magnetization at a fixed value for a certain time in the way of magnetization change with a constant change rate, magnetic losses widely changed with the keeping time. Analysis on these loss processes has shown that a clear difference has existed between the static and the dynamic magnetic domain structures and transfer between them has required the time and the energy. Experiments about these magnetizing processes should be continued.
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Report
(3 results)
Research Products
(12 results)