Magnetic nanoarrays on flexible substrates

In this work, we used nanosphere lithography to fabricate large area 2-D magnetic nanoparticle (MNP) arrays on a flexible polyimide substrate (Kapton). Samples were fabricated by assembling polystyrene (PS) spheres on thin films of Co capped with Au. Etched PS spheres were used to mask Co-Au particle arrays. The MNP arrays were subjected to superconducting quantum interference device measurements; flat samples (10 nm Co coated with 10 nm Au) exhibited an M _s of 117.3 emu g^-1, which was lower than the reported literature value for bulk Co (162.7 emu g^-1). When compared to the flat film, coercivity, H _c, increased in a linear fashion with respect to particle size. These preliminary results reveal that future investigations of the magnetic properties on flexible substrates should account for residual Co remaining in the polymeric material, the unique MNP shape, the effect of order (or lack or order) of the 2D array, and positioning with respect to the direction of the magnetic field.

The online version contains supplementary material available at 10.1557/s43580-021-00193-z.