Presentation Information
[7p-P03-38]Insulator thickness dependence of magnetocapacitance in magnetic tunnel junctions and calculation modeling
〇Ryuta Okazaki1, Yuto Shibata1, Mizuki Matsuzaka1, Mizuki Wakamoto1, Hiroaki Sukegawa2, Hideo Kaiju1,3 (1.Keio Univ., 2.NIMS, 3.Keio spin center)
Keywords:
TMC effect,insulator thickness dependence,magnetic tunnel junctions
We have achieved the largest tunnel magnetocapacitance (TMC) of over 650% in the high frequency region at room temperature in magnetic tunnel junctions (MTJs) consisting of a ferromagnetic-layer/insulator/ferromagnetic-layer. The TMC was remarkable at low frequencies and only about 50% at high frequencies. In this study, by using MTJs with a FeCo/MgO/FeCo structure with a thin insulator of MgO, the response of the electric dipole at high frequencies was enhanced, resulting in a significant improvement in TMC. This is due to the high-frequency response of the interfacial electric dipole based on the Debye-Fröhlich (DF) model. We also calculate the insulator thickness dependence of the TMC effect by the extended DF model. These findings contribute to a deeper understanding on the exact mechanism of the TMC effect, and the prospect of an increasingly large TMC at higher frequencies opens exciting opportunities for novel spintronic applications.