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Temperature dependence of spin-dependent tunneling conductance of magnetic tunnel junctions with half-metallic Co2MnSi electrodes
| Title: | Temperature dependence of spin-dependent tunneling conductance of magnetic tunnel junctions with half-metallic Co2MnSi electrodes |
| Authors: | Hu, Bing Browse this author | | Moges, Kidist Browse this author | | Honda, Yusuke Browse this author | | Liu, Hong-xi Browse this author | | Uemura, Tetsuya Browse this author →KAKEN DB | | Yamamoto, Masafumi Browse this author →KAKEN DB | | Inoue, Jun-ichiro Browse this author | | Shirai, Masafumi Browse this author →KAKEN DB |
| Issue Date: | 23-Sep-2016 |
| Publisher: | American Physical Society (APS) |
| Journal Title: | Physical Review B |
| Volume: | 94 |
| Issue: | 9 |
| Start Page: | 094428 |
| Publisher DOI: | 10.1103/PhysRevB.94.094428 |
| Abstract: | In order to elucidate the origin of the temperature (T) dependence of spin-dependent tunneling conductance (G) of magnetic tunnel junctions (MTJs), we experimentally investigated the T dependence of G for the parallel and antiparallel magnetization alignments, G(P) and G(AP), of high-quality Co2MnSi (CMS)/MgO/CMS MTJs having systematically varied spin polarizations (P) at 4.2 K by varying the Mn composition alpha in Co2Mn alpha Si electrodes that exhibited giant tunneling magnetoresistance ratios. Results showed that G(P) normalized by its value at 4.2 K exhibited a notable, nonmonotonic T dependence although its variation with T was significantly smaller than that of G(AP) normalized by its value at 4.2 K, indicating that an analysis of the experimental G(P)(T) is critical to revealing the origin of the T dependence of G. By analyzing the experimental G(P)(T), we clarified that both spin-flip inelastic tunneling via a thermally excited magnon and spin-conserving elastic tunneling in which P decays with increasing T play key roles. The experimental G(AP)(T), including its stronger T dependence for higher P at 4.2 K, was also consistently explained with this model. Our findings provide a unified picture for understanding the origin of the T dependence of G of MTJs with a wide range of P, including MTJs with high P close to a half-metallic value. |
| Rights: | ©2016 American Physical Society |
| Type: | article |
| URI: | http://hdl.handle.net/2115/63561 |
| Appears in Collections: | 情報科学院・情報科学研究院 (Graduate School of Information Science and Technology / Faculty of Information Science and Technology) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 山本 眞史
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