1:30 PM - 3:30 PM
▼ [9p-PB1-56] Enhancement of spin-orbit torque in W/CoFeB/MgO by controlling W resistivity
Keywords: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 (ξSL, ξFL), where ξSL is equivalent to the effective spin Hall angle. To achieve the efficient control of the magnetization orientation, a material system that exhibits large ξSL is desirable. W is a promising material exhibiting large ξSL and a recent study showed a variation of ξSL by a factor of 2-3 with W resistivity ρW in the range of 100-240 μΩcm. Here we study the SOT of the W/CoFeB/MgO heterostructures by controlling ρW over a wide range (180-730 μΩcm) and discuss the mechanism for SOT generation in the heterostructures.