Thickness dependence study of current-driven ferromagnetic resonance in   Y3Fe5O12/heavy metal bilayers
  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. 
Z. Fang, A. Mitra, A. L. Westerman, M. Ali, C. Ciccarelli, O.   Cespedes, B. J. Hickey and A. J. Ferguson
cond-mat.mes-hall