Thickness dependence study of current-driven ferromagnetic resonance in Y3Fe5O12/heavy metal bilayers

Z. Fang, A. Mitra, A. L. Westerman, M. Ali, C. Ciccarelli, O. Cespedes, B. J. Hickey, A. J. Ferguson
2017 Applied Physics Letters  
We use ferromagnetic resonance to study the current-induced torques in YIG/heavy metal bilayers. YIG samples with thickness varying from 14.8 nm to 80 nm, with Pt or Ta thin film on top, are measured by applying a microwave current into the heavy metals and measuring the longitudinal DC voltage generated by both spin rectification and spin pumping. From a symmetry analysis of the FMR lineshape and its dependence on YIG thickness, we deduce that the Oersted field dominates over spin-transfer torque in driving magnetization dynamics.
doi:10.1063/1.4977490 fatcat:myxvjaxkbvgldpfq2j6ntcjszm