Giant interfacial perpendicular magnetic anisotropy in MgO/CoFe/capping layer structures

Shouzhong Peng, Weisheng Zhao, Junfeng Qiao, Li Su, Jiaqi Zhou, Hongxin Yang, Qianfan Zhang, Youguang Zhang, Cecile Grezes, Pedram Khalili Amiri, Kang L. Wang

Research output: Contribution to journalArticlepeer-review

63 Citations (Scopus)

Abstract

Magnetic tunnel junction based on the CoFeB/MgO/CoFeB structures is of great interest due to its application in the spin-transfer-torque magnetic random access memory (STT-MRAM). Large interfacial perpendicular magnetic anisotropy (PMA) is required to achieve high thermal stability. Here, we use the first-principles calculations to investigate the magnetic anisotropy energy (MAE) of the MgO/CoFe/capping layer structures, where the capping materials include 5d metals Hf, Ta, Re, Os, Ir, Pt, and Au and 6p metals Tl, Pb, and Bi. We demonstrate that it is feasible to enhance PMA by using proper capping materials. Relatively large PMA is found in the structures with the capping materials of Hf, Ta, Os, Ir, and Pb. More importantly, the MgO/CoFe/Bi structure gives rise to giant PMA (6.09 mJ/m2), which is about three times larger than that of the MgO/CoFe/Ta structure. The origin of the MAE is elucidated by examining the contributions to MAE from each atomic layer and orbital. These findings provide a comprehensive understanding of the PMA and point towards the possibility to achieve the advanced-node STT-MRAM with high thermal stability.

Original languageEnglish
Article number072403
JournalApplied Physics Letters
Volume110
Issue number7
DOIs
Publication statusPublished - 2017 Feb 13

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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