Improving the perpendicular magnetic anisotropy (PMA) and voltage-controlled magnetic anisotropy (VCMA) properties are fundamentally important for the development of voltage-controlled magnetoresistive random access memories (VC-MRAM). Recently, we reported on a large increase in PMA at an Fe/MgO interface brought about by inserting an ultrathin LiF layer at the interface. In this paper, we investigate the PMA, VCMA, and TMR properties in MTJs with an Ir-doped ultrathin ferromagnetic layer and a LiF/MgO hybrid tunneling barrier. We observed a clear increase in the interfacial PMA by a factor of 2.5 when an ultrathin 0.25 nm LiF layer was inserted. A large VCMA coefficient, exceeding −300 fJ/Vm, was also achieved while maintaining the high TMR ratio and high interfacial PMA. These results demonstrate the high potential of interface engineering using ultrathin LiF layers for spintronic devices.
Voltage-controlled magnetic anisotropy effect through a LiF/MgO hybrid tunneling barrier
Note: This paper is part of the APL Special Collection on Magneto-ionic and electrostatic gating of magnetism: Phenomena and devices.
Takayuki Nozaki, Tomohiro Nozaki, Tatsuya Yamamoto, Makoto Konoto, Atsushi Sugihara, Kay Yakushiji, Shinji Yuasa; Voltage-controlled magnetic anisotropy effect through a LiF/MgO hybrid tunneling barrier. Appl. Phys. Lett. 24 October 2022; 121 (17): 172401. https://doi.org/10.1063/5.0122192
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