| Presentation | 2007-02-02 Fabrication of epitaxial magnetic tunnel junctions with a Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al thin film and a MgO tunnel barrier and their tunnel magnetoresistance characteristics Takao MARUKAME, Takayuki ISHIKAWA, Ken-ichi MATSUDA, Tetsuya UEMURA, Masafumi YAMAMOTO, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | Fully epitaxial magnetic tunnel junctions (MTJs) were fabricated with a full-Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al (CCFA) thin film and a MgO tunnel barrier. Pseudo-spin-valve-type, fully epitaxial CCFA/MgO/Co_<50>Fe_<50> MTJs with a CCFA film composition close to the stoichiometric one demonstrated high tunnel magnetoresistance (TMR) ratios of 90% at room temperature (RT) and 240% at 4.2 K. From this result, it was suggested that the CCFA film composition close to stoichiometric one is essential for obtaining high spin polarizations in CCFA thin films. The fully epitaxial CCFA/MgO/Co_<50>Fe_<50> MTJs with exchange biasing, where a Co_<50>Fe_<50> upper electrode was used in a synthetic ferrimagnetic Co_<50>Fe_<50>/Ru/Co_<90>Feio trilayer exchange-biased with an IrMn layer through the Co_<90>Feio/IrMn interface, exhibited high TMR ratios of 109% at RT and 317% at 4.2 K. From the obtained TMR ratio of 317% at 4.2 K, a high tunneling spin polarization of 0.88 at 4.2 K was estimated for epitaxial CCFA films with the B2 structure. These results confirm the promise of an epitaxial MTJ using a Co-based full-Heusler alloy as a key device structure for utilizing the potentially high spin polarization of this material system. |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Magnetic tunnel junction / Half-metallic ferromagnet / Heusler alloy / Epitaxial growth |
| Paper # | ED2006-249,SDM2006-237 |
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| Committee | ED |
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| Conference Date | 2007/1/25(1days) |
| Place (in Japanese) | (See Japanese page) |
| Place (in English) | |
| Topics (in Japanese) | (See Japanese page) |
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| Paper Information | |
| Registration To | Electron Devices (ED) |
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| Language | JPN |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Fabrication of epitaxial magnetic tunnel junctions with a Heusler alloy Co_2Cr_<0.6>Fe_<0.4>Al thin film and a MgO tunnel barrier and their tunnel magnetoresistance characteristics |
| Sub Title (in English) | |
| Keyword(1) | Magnetic tunnel junction |
| Keyword(2) | Half-metallic ferromagnet |
| Keyword(3) | Heusler alloy |
| Keyword(4) | Epitaxial growth |
| 1st Author's Name | Takao MARUKAME |
| 1st Author's Affiliation | Division of Electronics for Informatics, Hokkaido University() |
| 2nd Author's Name | Takayuki ISHIKAWA |
| 2nd Author's Affiliation | Division of Electronics for Informatics, Hokkaido University |
| 3rd Author's Name | Ken-ichi MATSUDA |
| 3rd Author's Affiliation | Division of Electronics for Informatics, Hokkaido University |
| 4th Author's Name | Tetsuya UEMURA |
| 4th Author's Affiliation | Division of Electronics for Informatics, Hokkaido University |
| 5th Author's Name | Masafumi YAMAMOTO |
| 5th Author's Affiliation | Division of Electronics for Informatics, Hokkaido University |
| Date | 2007-02-02 |
| Paper # | ED2006-249,SDM2006-237 |
| Volume (vol) | vol.106 |
| Number (no) | 520 |
| Page | pp.pp.- |
| #Pages | 6 |
| Date of Issue | |