Regensburg 2019 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 32: Magnetic recording, sensors and other devices

MA 32.2: Vortrag

Mittwoch, 3. April 2019, 12:15–12:30, H53

Mechanically controlled magnetization reversal in single-domain particles — •Thomas Mühl, Stefan Philippi, Heike Schlörb, Dipankar Mukherjee, and Bernd Büchner — IFW Dresden, Dresden, Germany

Magnetization reversal of small ferromagnetic particles requires to overcome an energy barrier which is mainly defined by the magnetic anisotropy. Usual reversal stimuli include the application of static or time-dependent external magnetic fields, thermal activation, spin transfer torque, or combinations thereof. Here, we report on quasi-periodic magnetization reversal in single-domain particles that are exposed to a constant magnetic field perpendicular to the magnet's easy axis. The continuous sequence of reversals is induced by torsional oscillations of the magnet's anisotropy landscape, which are caused by angular oscillations of the magnet's body. In our experiments, a nickel nanowire constitutes both a mechanical resonator and a nanomagnetic sample with uniaxial anisotropy. We measure the transient flexural vibration behavior by electron beam based methods and find strong signatures of periodic magnetization switching between two magnetic states of the nanowire. Furthermore, we extend our approach towards mechanically-controlled single reversals of magnetization that are induced by pulsed mechanical excitation. The latter might be the foundation for a novel ansatz for energy-efficient magnetic data storage.

Ref.: S. Philippi, H. Schlörb, D. Mukherjee, B. Büchner, T. Mühl, Nanotechnology 29, 405503 (2018).