| Presentation | 2010-03-12 Structural Variation and Control of Magnetic Properties of MnBi Thin Films by Kr^+ Ion Irradiation Seisen JYO, Takeshi KATO, Satoshi IWATA, Shigeru TSUNASHIMA, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | MnBi(15nm) thin films were prepared by the magnetron sputtering of Mn/Bi multilayers followed by vacuum annealing of 350℃, and the variation of their structures and magnetic properties with 30 keV Kr^+ ion irradiation was studied. The Mn_<52>Bi_<48>(15nm) film exhibited a magnetization of 180 emu/cc, which was 1/3 of the reported value, but it exhibited a large coercivity of 10 kOe resulting from large perpendicular anisotropy of this film. The magnetization and coercivity of the Mn_<52>Bi_<48> film were disappeared after a low ion dose of 3.1 x 10^<14> ions/cm^2. However, the existence of NiAs type MnBi phase and uni-directional anisotropy was confirmed by X-ray diffraction and torque magnetometer, respectively, even after the ion irradiation of 1 x 10^<15> ions/cm^2. From atomic force microscope and magnetic force microscope observations, there existed convex surface structures with a height of ～ 50 nm on the MnBi films, and MnBi phase underneath the convex structures exhibited ferromagnetism even after the ion irradiation of 1 x 10^<15>ions/cm^2. The surviving MnBi phases were considered to be magnetically isolated, and the existence of the isolated MnBi phases explained the variation of the structure and magnetic properties with the ion irradiation. From these results, transformation between ferromagnetic and nonmagnetic MnBi alloys by a low dose ion irradiation of ～ 3 x 10^<14> ions/cm^2 was expected. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Ion Irradiation / Bit Patterned Media / MnBi Thin Films / Surface Flatness |
| Paper # | MR2009-62 |
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| Conference Information | |
| Committee | MR |
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| Conference Date | 2010/3/5(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Magnetic Recording (MR) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Structural Variation and Control of Magnetic Properties of MnBi Thin Films by Kr^+ Ion Irradiation |
| Sub Title (in English) | |
| Keyword(1) | Ion Irradiation |
| Keyword(2) | Bit Patterned Media |
| Keyword(3) | MnBi Thin Films |
| Keyword(4) | Surface Flatness |
| 1st Author's Name | Seisen JYO |
| 1st Author's Affiliation | Graduate School of Engineering, Nagoya University() |
| 2nd Author's Name | Takeshi KATO |
| 2nd Author's Affiliation | Graduate School of Engineering, Nagoya University |
| 3rd Author's Name | Satoshi IWATA |
| 3rd Author's Affiliation | Graduate School of Engineering, Nagoya University |
| 4th Author's Name | Shigeru TSUNASHIMA |
| 4th Author's Affiliation | Graduate School of Engineering, Nagoya University |
| Date | 2010-03-12 |
| Paper # | MR2009-62 |
| Volume (vol) | vol.109 |
| Number (no) | 433 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |