Magnetization switching assisted by out-of-plane ultrafast pulsed field in high perpendicular anisotropy nanostructures

A microwave test structure has been designed to study the magnetization switching assisted by ultrafast out-of-plane field pulses in perpendicular anisotropy nanostructures. Using extraordinary Hall effect (EHE), we measure quasistatic hysteresis loops while continuously applying field pulses of given amplitude (550Oe), variable duration (0.2-10 ns) and repetition frequency (1 Hz-100 kHz). The maximum measured shift in coercive field exceed 200 Oe for 10 ns pulse. The shift decreases with decreasing pulse duration and repetition frequency and increases linearly with the pulse amplitude, while switching probability increases with pulse duration. (c) 2004 Elsevier B.V. All rights reserved.