[9p-PB1-1~80] 10 スピントロニクス・マグネティクス（ポスター講演）

▼ [9p-PB1-56] Enhancement of spin-orbit torque in W/CoFeB/MgO by controlling W resistivity

〇Kaito Furuya¹、Yutaro Takeuchi¹、Yu Takahashi¹、Chaoliang Zhang^1,2,3,4、Buturin Jinnai³、Syunsuke Fukami^1,3,4,5,6,7、Hideo Ohno^1,3,4,5,6,7 (1.RIEC, Tohoku Univ.、2.FRIS、3.CSIS、4.CIES、5.CSRN、6.CSIS (CRN)、7.WPI-AIMR)

キーワード：spintronics, spin Hal angle, tungsten

Spin-orbit torques (SOT) allows an electrical control of a magnetization orientation in magnetic heterostructures. SOT has two components with different symmetries: the Slonczewski-like (SL) and field-like (FL) torques, whose magnitudes are characterized as spin-orbit torque efficiency parameters (ξ_SL, ξ_FL), where ξ_SL is equivalent to the effective spin Hall angle. To achieve the efficient control of the magnetization orientation, a material system that exhibits large ξ_SL is desirable. W is a promising material exhibiting large ξ_SL and a recent study showed a variation of ξ_SL by a factor of 2-3 with W resistivity ρ_W in the range of 100-240 μΩcm. Here we study the SOT of the W/CoFeB/MgO heterostructures by controlling ρ_W over a wide range (180-730 μΩcm) and discuss the mechanism for SOT generation in the heterostructures.