講演情報

[23a-12D-4]Precise analysis of angle-dependent spin-orbit torque for electrodeposited CoPt thin film by integrating the low and high field second harmonic Hall measurements

〇Tongshuang Huang1, Yota Takamura1, Shinji Isogami2, Takanori Shirokura1, Yuta Saito1, Md. Mahmudul Hasan3, Saito Mikiko3, Shinya Kasai2, Shigeki Nakagawa1 (1.Tokyo Tech., 2.NIMS, 3.Waseda Univ.)

キーワード:

spin-orbit torque、Electrodeposition technique、2nd harmonic Hall measurement

Three-dimensional domain wall motion memory (3D-DWMM), an emerging non-volatile memory employing spin-orbit torque (SOT) technology for data writing, was proposed recently. Nanopillars with a high aspect ratio were fabricated by applying electrodeposition, forming the unit cell of 3D-DWMM. We have demonstrated CoPt thin film with perpendicular magnetic anisotropy and adjustable magnetic properties. The feasibility of SOT in the electrodeposited CoPt needs to be confirmed. In the previous research, we demonstrated SOT by low-field 2nd harmonic Hall measurement. The contribution of the thermal-electric effect was not considered. In this study, we introduce a high-field 2nd harmonic Hall measurement to disentangle the thermal effect signal and SOT signal. Due to limitations of local optimum fitting in the high-field analysis, we integrate it with low-field data to obtain results applicable to general external magnetic fields (Hext) across both low-field and high-field. The combined approach successfully distinguishes the SOT signal from the thermal signal, allowing precise estimation of the effective field and spin Hall angle.