2005 Fiscal Year Final Research Report Summary
Synthesis of High Performance Thin Film Magnet on Semiconductor Substrate for the Micromagnetic Devices
| Project/Area Number |
16510098
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Microdevices/Nanodevices
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| Research Institution | Nagoya Institute of Technology |
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Principal Investigator |
ADACHI Nobuyasu Nagoya Institute of Technology, Associate Professor, 大学院・工学研究科, 助教授 (90262956)
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| Co-Investigator(Kenkyū-buntansha) |
OSATO Hitoshi Nagoya Institute of Technology, Professor, 大学院・工学研究科, 教授 (20024333)
GOMI Manabu Nagoya Institute of Technology, Professor, 大学院・工学研究科, 教授 (80126276)
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| Project Period (FY) |
2004 – 2005
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| Keywords | rare earth thin film magnet / high coercivity / MEMS / RF sputtering / post-annealing / Si substrate / single magnetic domain / c-axis preferential orientation |
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| Research Abstract |
We successfully synthesized thin films of Nd-Fe-B rare earth magnets with coercive force of about 15 kOe on Si(111) single crystal substrate by RF sputtering and post annealing technique. Preparation of thin film magnet on semiconductor substrate has great advantage for the practical application of MEMS devices. We inserted the buffer layer of MoSi_2 between the substrate and Nd-Fe-B layer with approximately 2 micron thickness. We consider that the buffer layer has a roll to depress the thermal strain. The Ti top layer was coated for the protect from oxidation of the Nd-Fe-B layer. The as-deposited films shows the amorphous phase. After annealing at 650 degreeC by infrared radiation in vacuum atmosphere, the Nd_2Fe_14B phase was well crystallized in the film. The XRD pattern showed (00l) diffraction and the strong (410) peak was also observed. The magnetic hysteresis showed the isotropic in the magnetic field parallel and perpendicular to the film plane. This result come from the random orientation of c-axis. The XRD analysis is agreement with the insufficient c-axis orientations. However, the coercive force of the film shoed the large value of aboout 15 kOe. The SEM and MFM observation of the film suggested the single magnetic domain structure with 200-350 nm diameter was realized. Although the realization of the c-axis preferential orientation of the film remains a subject matter to overcome, the high coercivity of the film is good property for the concrete application of the micromotor or microactuator in the MEMS devices.
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