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Updated: Apr 15, 2026

Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques
Published on: July 2, 2018
Composite microdiscs with a magnetic belt: preparation, chaining properties, and use as switchable catalyst carriers
Matti Knaapila1,2, Henrik Høyer3, Geir Helgesen1,4
1†Physics Department, Institute for Energy Technology, NO-2027 Kjeller, Norway.
Abstract:
We describe an emulsion-based preparation of patchy composite particles (diameter of 100-500 μm) consisting of a disclike epoxy core and a belt of porous polystyrene particles (diameter of 30 μm) with magnetite within the pores. Compared to the magnetically uniform polystyrene particles, the spontaneous aggregation of composite particles is suppressed when dispersed into liquid, which is attributed to the increased particle size, reduced magnetic susceptibility, and the shape of the magnetic domain distribution within the particles (spherical versus a belt). When the composite particles are coated by platinum-palladium layer we demonstrate they can be employed as switchable catalyst carriers, moving from one liquid phase to another when controlled by an external magnetic field.

