Time-Resolved Spin Torque Switching and Enhanced Damping in Py/Cu/Py Spin-Valve Nanopillars

Abstract

We report time-resolved measurements of current-induced reversal of a free magnetic layer in Py/Cu/Py elliptical nanopillars at temperatures T = 4.2 K to 160 K. Comparison of the data to Landau-Lifshitz-Gilbert macrospin simulations of the free layer switching yields numerical values for the spin torque and the Gilbert damping parameters as functions of T. The damping is strongly T-dependent, which we attribute to the antiferromagnetic pinning behavior of a thin permalloy oxide layer around the perimeter of the free layer. This adventitious antiferromagnetic pinning layer can have a major impact on spin torque phenomena.

5 pages, 4 figures

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Cited by in corpus (16)

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• Effect of Polarized Current on the Magnetic State of Antiferromagnet
• Large-amplitude coherent spin waves exited by spin-polarized current in nanoscale spin valves
• Spin-Torque Ferromagnetic Resonance Measurements of Damping in Nanomagnets
• Single-shot time-domain studies of spin-torque-driven switching in magnetic tunnel junctions
• Time-Domain Studies of Very-Large-Angle Magnetization Dynamics Excited by Spin Transfer Torques
• Distribution of the magnetization reversal duration in sub-ns spin-transfer switching
• Spin-transfer-torque resonant switching and injection locking in presence of a weak external microwave field for spin valves with perpendicular materials
• Biased quasi ballistic spin torque magnetization reversal
• Enhancement in spin-torque efficiency by nonuniform spin current generated within a tapered nanopillar spin valve
• Microwave excitations associated with a wavy angular dependence of the spin transfer torque : model and experiments
• Effective attraction induced by repulsive interaction in a spin-transfer system
• Feedback control of noise in spin valves by the spin-transfer torque
• Ballistic vs Diffusive Transport in Current-Induced Magnetization Switching
• Analytical solutions for two-level systems with damping
• Current-induced reversal in magnetic nanopillars passivated by silicon