Vineet Barwal
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science)
;
Hirofumi Suto
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
;
Ryo Toyama
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
;
Kodchakorn Simalaotao
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
;
Taisuke Sasaki
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
;
Yoshio Miura
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
;
Yuya Sakuraba
(Research Center for Magnetic and Spintronic Materials, National Institute for Material Science
)
説明:
(abstract)Half-metallic ferromagnetic Heusler alloys having high spin polarization are promising candidates to realize large magnetoresistance (MR) ratio and high spin-transfer torque (STT) efficiency in next-generation spintronic devices. Since the Heusler alloy properties are sensitive to composition, optimizing the composition is crucial for enhancing device performance. Here, we report the fabrication of high-performance current-perpendicular-to-plane giant magnetoresistance (CPP-GMR) devices using Co2MnxFe1−xGe (0 ≤ x ≤ 1) Heusler alloy, employing a high-throughput and detailed composition optimization method. The method combined composition-gradient films and local measurements to enable the composition variation from Co2FeGe to Co2MnGe to be efficiently studied on a single library sample with a small composition interval. The CPP-GMR devices fabricated from stacks annealed at 250○C showed a clear composition dependence of MR with the maximum of MR ratio ∼38% in the Mn-rich region of x = 0.85. By increasing the annealing temperature to 350○C, the MR ratio increased to ∼45% along with high STT efficiency ∼0.6 in the broad composition range of 0.2 ≤ x ≤ 0.7. The optimal composition for the highest MR changed with annealing temperature because of the stability of the GMR stack being higher in the lower x range. The record high MR for the all-metal CPP-GMRdevices, at low annealing temperature of 250○C was achieved by the detailed composition optimization. These results present the high potential of Co2MnxFe1−xGe and provide a comprehensive guidance on the composition optimization for achieving large MR ratio and high STT efficiency in the CPP-GMR devices.
権利情報:
キーワード: Spin-transfer-torque, Spintronic devices, Giant magnetoimpedance materials
刊行年月日: 2024-11-01
出版者: AIP Publishing
掲載誌:
研究助成金:
原稿種別: 著者最終稿 (Accepted manuscript)
MDR DOI: https://doi.org/10.48505/nims.5289
公開URL: https://doi.org/10.1063/5.0226638
関連資料:
その他の識別子:
連絡先:
更新時刻: 2025-03-14 13:30:16 +0900
MDRでの公開時刻: 2025-01-22 16:30:16 +0900
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20250121_MDR_MS_Large MR and high STT achived in CMFG.pdf
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サイズ | 3.04MB | 詳細 |