  Magnetic Janus particles (MJPs), fabricated by covering a non-magnetic
spherical particle with a hemispherical magnetic in-plane exchange-bias layer
system cap, display an onion magnetization state for comparably large diameters
of a few microns. In this work, the motion characteristics of these MJPs will
be investigated when they are steered by a magnetic field landscape over
prototypical parallel-stripe domains, dynamically varied by superposed external
magnetic field pulse sequences, in an aqueous medium. We demonstrate, that due
to the engineered magnetization state in the hemispherical cap, a comparably
fast, directed particle transport and particle rotation can be induced.
Additionally, by modifying the frequency of the applied pulse sequence and the
strengths of the individual field components, we observe a possible separation
between a combined or an individual occurrence of these two types of motion.
Our findings bear importance for lab-on-a-chip systems, where particle
immobilization on a surface via analyte bridges shall be used for low
concentration analyte detection and a particle rotation over a defined position
of a substrate may dramatically increase the immobilization (and therefore
analyte detection) probability.
