Regensburg 2004 – wissenschaftliches Programm

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MA: Magnetismus

MA 28: Spindynamik / Ummagnetisierungsvorg
änge

MA 28.6: Vortrag

Donnerstag, 11. März 2004, 16:30–16:45, H23

NANOSECOND TIME-SCALE SWITCHING OF THIN FILM PERMALLOY ELEMENTS — •Dmitry Chumakov, Rudolf Schäfer, Jeffrey McCord, and Ludwig Schultz — IFW-Dresden, Helmholtzstr. 20, D-01069 Dresden, Germany

We have studied the dynamic magnetization switching behaviour of thin film Permalloy elements by gated ICCD camera-based time-resolved wide-field Kerr microscopy. The structures were subject to pulsed magnetic fields of different strengths from 1600 A/m to 5200 A/m. Their reversal was observed with 250 ps time-resolution. By interpreting the experimental results we point out the peculiarities of the nanosecond timescale switching. Like in the quasistatic case, the dynamic remagnetization process is dominated by the generation of concertina-like domain patterns. Whereas such No-dqblockedNo-dq domains decay irreversibly in several steps during quasistatic switching, the blocking is resolved by continuous rotation in a locally inhomogeneous way for dynamic switching. This process lasts several nanoseconds and leads to significant delays in element switching. The influence of magnetic field amplitude, rise-time, and element shape on the switching behaviour will be shown at various examples.