Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation
The influence of the sidewall damage on the thermal stability factor (Δ) of quad-interface magnetic tunnel junctions (quad-MTJs) was investigated through a string method-based micromagnetic simulation. The quad-MTJs consist of a reference layer/MgO-barrier/CoFeB/middle-MgO/CoFeB/MgO-cap, which has f...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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AIP Publishing LLC
2022-12-01
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| Series: | AIP Advances |
| Online Access: | http://dx.doi.org/10.1063/5.0112741 |
| _version_ | 1797947386688962560 |
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| author | Hiroshi Naganuma Hiroaki Honjo Chioko Kaneta Koichi Nishioka Shoji Ikeda Tetsuo Endoh |
| author_facet | Hiroshi Naganuma Hiroaki Honjo Chioko Kaneta Koichi Nishioka Shoji Ikeda Tetsuo Endoh |
| author_sort | Hiroshi Naganuma |
| collection | DOAJ |
| description | The influence of the sidewall damage on the thermal stability factor (Δ) of quad-interface magnetic tunnel junctions (quad-MTJs) was investigated through a string method-based micromagnetic simulation. The quad-MTJs consist of a reference layer/MgO-barrier/CoFeB/middle-MgO/CoFeB/MgO-cap, which has four CoFeB/MgO interfaces to enhance the interfacial perpendicular magnetic anisotropy for large Δ. Experimentally obtained magnetic parameters at room temperature [e.g., saturation magnetization (Ms), stiffness constant (As), interfacial perpendicular magnetic anisotropy constants (Ki), and exchange coupling (Jex)] in blanket multilayer films of the quad-MTJs were used in micromagnetic simulation. The influence of the sidewall damage on the quad-MTJs, which is difficult to be analyzed in the experimental way, was investigated. The quad-MTJs without damaged layers having relatively higher Ki show the split of the energy barrier into two, resulting in a decrease in Δ. When the decrease in magnetic anisotropy energy (Eani) is more than the increase in the static magnetic energy (Esta), the antiferromagnetically (AF) coupled state of two free layers is formed at the midpoint to minimize the total energy (Eall). This causes the split of the energy barrier. The sidewall damage plays a role in lowering Ki in each layer, consequently avoiding the formation of the AF state. Note that the value of Δ with the sidewall damage, which shows the unified energy barrier, is comparable to non-damaged Δ, which shows the split of the energy barrier; these quad-MTJs have the same volume of free layers. |
| first_indexed | 2024-04-10T21:25:56Z |
| format | Article |
| id | doaj.art-41795573fd574cc48385f4879a4ab3f3 |
| institution | Directory Open Access Journal |
| issn | 2158-3226 |
| language | English |
| last_indexed | 2024-04-10T21:25:56Z |
| publishDate | 2022-12-01 |
| publisher | AIP Publishing LLC |
| record_format | Article |
| series | AIP Advances |
| spelling | doaj.art-41795573fd574cc48385f4879a4ab3f32023-01-19T16:47:10ZengAIP Publishing LLCAIP Advances2158-32262022-12-011212125317125317-1010.1063/5.0112741Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulationHiroshi Naganuma0Hiroaki Honjo1Chioko Kaneta2Koichi Nishioka3Shoji Ikeda4Tetsuo Endoh5Center for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanCenter for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanCenter for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanCenter for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanCenter for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanCenter for Innovative Integrated Electronic System (CIES), Tohoku University, 468-1, Aoba, Aramaki, Aoba-ku, Sendai 980-8572, JapanThe influence of the sidewall damage on the thermal stability factor (Δ) of quad-interface magnetic tunnel junctions (quad-MTJs) was investigated through a string method-based micromagnetic simulation. The quad-MTJs consist of a reference layer/MgO-barrier/CoFeB/middle-MgO/CoFeB/MgO-cap, which has four CoFeB/MgO interfaces to enhance the interfacial perpendicular magnetic anisotropy for large Δ. Experimentally obtained magnetic parameters at room temperature [e.g., saturation magnetization (Ms), stiffness constant (As), interfacial perpendicular magnetic anisotropy constants (Ki), and exchange coupling (Jex)] in blanket multilayer films of the quad-MTJs were used in micromagnetic simulation. The influence of the sidewall damage on the quad-MTJs, which is difficult to be analyzed in the experimental way, was investigated. The quad-MTJs without damaged layers having relatively higher Ki show the split of the energy barrier into two, resulting in a decrease in Δ. When the decrease in magnetic anisotropy energy (Eani) is more than the increase in the static magnetic energy (Esta), the antiferromagnetically (AF) coupled state of two free layers is formed at the midpoint to minimize the total energy (Eall). This causes the split of the energy barrier. The sidewall damage plays a role in lowering Ki in each layer, consequently avoiding the formation of the AF state. Note that the value of Δ with the sidewall damage, which shows the unified energy barrier, is comparable to non-damaged Δ, which shows the split of the energy barrier; these quad-MTJs have the same volume of free layers.http://dx.doi.org/10.1063/5.0112741 |
| spellingShingle | Hiroshi Naganuma Hiroaki Honjo Chioko Kaneta Koichi Nishioka Shoji Ikeda Tetsuo Endoh Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation AIP Advances |
| title | Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation |
| title_full | Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation |
| title_fullStr | Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation |
| title_full_unstemmed | Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation |
| title_short | Influence of sidewall damage on thermal stability in quad-CoFeB/MgO interfaces by micromagnetic simulation |
| title_sort | influence of sidewall damage on thermal stability in quad cofeb mgo interfaces by micromagnetic simulation |
| url | http://dx.doi.org/10.1063/5.0112741 |
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