| Project/Area Number |
21K18810
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| Research Category |
Grant-in-Aid for Challenging Research (Exploratory)
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| Allocation Type | Multi-year Fund |
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| Review Section |
Medium-sized Section 26:Materials engineering and related fields
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| Research Institution | Tohoku University |
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Principal Investigator |
Cao Yang 東北大学, 学際科学フロンティア研究所, 助教 (50804598)
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| Co-Investigator(Kenkyū-buntansha) |
増本 博 東北大学, 学際科学フロンティア研究所, 教授 (50209459)
小林 伸聖 公益財団法人電磁材料研究所, その他部局等, 研究員 (70205475)
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| Project Period (FY) |
2021-07-09 – 2023-03-31
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| Project Status |
Completed (Fiscal Year 2022)
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| Budget Amount *help |
¥6,370,000 (Direct Cost: ¥4,900,000、Indirect Cost: ¥1,470,000)
Fiscal Year 2022: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2021: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
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| Keywords | dielectric relaxation / granular dielectrics / electric field / electron tunneling / metal-ceramic composites / charge tunneling / nanogranular composites / dielectrtic properties / magnetic field / Nanogranular structure / Magneto-dielectric / dielectric tunability / spin-dependent tunneling |
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| Outline of Research at the Start |
The recently discovered tunneling magneto-dielectric (TMD) effect as well as the dielectric tunability (i.e., tunneling electro-dielectric, TED) open a new view in multifunctional nanogranular films. In this proposal, completely new tunneling electro-magneto-dielectric properties will be explored.
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| Outline of Final Research Achievements |
I have developed novel dielectric nanogranular materials that allow for the tuning of the dielectric relaxation frequency (fr) in the AC transport response using a DC electric field. These materials have the potential to simplify and miniaturize device structures such as RF low pass filters and antennas. The structure consists of magnetic metal nanoparticles dispersed in an insulating matrix. By applying a direct current electric field, it is possible to adjust the fr within a specific frequency range. Interestingly, increasing the electric field initially shifts the fr towards the low-frequency side before moving to the high-frequency side.
To address this issue, I developed an asymmetric electron tunneling model, which provides an explanation for the observed results. I have also theoretically investigated the dielectric properties based on the asymmetric electron tunneling model, taking into account the size difference between granular pairs.
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| Academic Significance and Societal Importance of the Research Achievements |
This work provide insights into the electric polarisation of disordered granular solids to electric fields associated with nanometric structures, which is of importance in the field of dielectric and spintronics physics and may have application in compact filters and antennas.
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