Fabrication of Single Layer Nano/Microsphere Templates Using a Dry Rubbing Method

The geometry of magnetic thin films on hexagonally close-packed single-layer nano/microsphere templates induces unique magnetic switching behavior with potential applications in data storage devices, spintronics, and sensors. While several techniques exist for creating such templates, this study employs a manual rubbing method using a polydimethylsiloxane (PDMS) stamp to quickly achieve hexagonally close-packed single layer template. 30 nm nanocap structures of Permalloy or Samarium Cobalt were made by sputtering deposition. Spheres with different diameters and materials are tested to optimize the conditions to obtain large uniform coverage in the template. Among various templates, one with 800 nm polystyrene spheres and another with 10 µm silica spheres achieved extensive coverage, although notable stacking issues were observed. When reusing the same PDMS stamp the second sample displayed a smaller, more concentrated area of single-layer spheres. When the PDMS stamp was examined after first use it was observed that a substantial number of spheres had been retained with stacking of multiple layers. Upon the second use, most of the multiple layers were rubbed off, leaving only a single layer of particles on the PDMS stamp.