Thermal behavior of spin-current generation in PtxCu1-x devices characterized through spin-torque ferromagnetic resonance
Grayson Dao Hwee Wong, Wai Cheung Law, Funan Tan, Wei Liang Gan, Calvin Ching Ian Ang, Zhan Xu, C. S. Seet, Wen Siang Lew
Abstract
Abstract High temperature studies of spin Hall effect have often been neglected despite its profound significance in real-world devices. In this work, high temperature spin torque ferromagnetic resonance measurement was performed to evaluate the effects of temperature on the Gilbert damping and spin Hall efficiency of Pt x Cu 1− x . When the temperature was varied from 300 K to 407 K, the Gilbert damping was relatively stable with a change of 4% at composition x = 66%. Alloying Pt and Cu improved the spin Hall efficiency of Pt 75 Cu 25 /Co/Ta by 29% to a value of 0.31 ± 0.03 at 407 K. However, the critical switching current density is dependent on the ratio between the Gilbert damping and spin Hall efficiency and the smallest value was observed when x = 47%. It was found that at this concentration, the spin transparency was at its highest at 0.85 ± 0.09 hence indicating the importance of interfacial transparency for energy efficient devices at elevated temperature.