Dresden 2014 – wissenschaftliches Programm

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MA: Fachverband Magnetismus

MA 19: Poster I

MA 19.18: Poster

Dienstag, 1. April 2014, 13:00–15:30, P1

Interaction Effects in Micro- and Nanoscale Magnetic Samples studied by First Order Reversal Curves — •Luigi Ventura¹, Martin Lonsky¹, Merlin Pohlit¹, Yuzo Ohno², Hideo Ohno², and Jens Müller¹ — ¹Physikalisches Institut, Goethe-Universität, Frankfurt (M), Germany — ²Laboratory for Nanoelectronics and Spintronics, Tohoku University, Sendai, Japan

Magnetic hysteresis is usually measured to determine sample-specific parameters such as the coercive field and the remanent magnetization and provides a measure of the bulk magnetic properties. Pike et al. have developed a method to gain more insight into magnetic interaction effects by the acquisition of a class of minor loops known as first order reversal curves (FORCs) [1]. Here, we discuss the application of the FORC method to micro- and nano-sized magnetic structures by combining it with micro-Hall magnetometry. The latter is an ultra-sensitive technique suitable for measuring small arrays and even individual magnetic particle positioned on top of the Hall sensor. Our sensors are based on a high-mobility two-dimensional electron gas in a GaAs/AlGaAs heterostructure and allow for measuring a Hall voltage which is proportional to the z-component of the local magnetic stray field. We discuss different magnetic systems, as e.g. the interaction between individual ferromagnetic micro-grains or coupling effects in an artificial spin-ice structure.
C. R. Pike et al., J. Appl. Physics 85, 9 (1999).