講演情報
[17p-K102-10]Effect of Pt and Bi on the spin Hall angle in topological semimetal YPtBi
〇Sho Kagami1, Ohiro Fujie1, Daiki Ito1, Quang Le2, Brian York2, Cherngye Hwang2, Xiaoyong Liu2, Son Le2, Maki Maeda3, Tuo Fan3, Yu Tao3, Hisashi Takano3, Pham Nam Hai1 (1.Institute of Science Tokyo, 2.Western Digital Inc., Great Oaks, 3.Western Digital Inc., Fujisawa)
キーワード：
half-Heusler alloy、topological semimetal、spin Hall effect
We study the fine tuning of Pt and Bi composition and reveal their role on the electrical and spintronic properties of the half-Heusler topological semimetal YPtBi. We have deposited, from the bottom to the top, YPtBi (7 nm) / Pt (0.8 nm) / Co (0.8 nm) / Pt (0.8 nm) / MgAl2O4 (4nm) / Ta (1 nm), and used the second harmonic Hall measurement technique to evaluate the effective spin Hall angle of YPtBi in Hall bar devices. We observe that Pt has little effect on the electrical conductivity of YPtBi, but slightly increasing Pt/Y to about 1.1 can enhance both the spin Hall angle and the spin Hall conductivity significantly. Meanwhile, we observe that Bi has little effect on the spin Hall conductivity, but has large effect on the electrical conductivity of YPtBi and consequently, the spin Hall angle. By tuning Bi/Y to about 1.1, we can reduce the electrical conductivity of YPtBi to 0.3 * 10(5) S/m and maximize the effective spin Hall angle ~ 4.0.