Time-Resolved X-ray Microscopy of Spin-Torque-Induced Magnetic Vortex Gyration

Abstract

Time-resolved X-ray microscopy is used to image the influence of alternating high-density currents on the magnetization dynamics of ferromagnetic vortices. Spin-torque induced vortex gyration is observed in micrometer-sized permalloy squares. The phases of the gyration in structures with different chirality are compared to an analytical model and micromagnetic simulations, considering both alternating spinpolarized currents and the current's Oersted field. In our case the driving force due to spin-transfer torque is about 70% of the total excitation while the remainder originates from the current's Oersted field. This finding has implications to magnetic storage devices using spin-torque driven magnetization switching and domain-wall motion.

10 pages, 3 figures

References in corpus (4)

• Magnetic Vortex Resonance in Patterned Ferromagnetic Dots
• Ultrafast Vortex-Core Reversal Dynamics in Ferromagnetic Nanodots
• Current-induced magnetic vortex core switching in a Permalloy nanodisk
• Harmonic oscillator model for current- and field-driven magnetic vortices

Cited by in corpus (5)

• Universal criterion and phase diagram for switching a magnetic vortex core in soft magnetic nanodots
• Switching magnetic vortex core by a single nanosecond current pulse
• Electrical rectification effect in single domain magnetic microstrips: a micromagnetics-based analysis
• Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin Torque
• Probing the spin polarization of current by soft X-ray imaging of current-induced magnetic vortex dynamics