Pattern transfer nanomanufacturing using magnetic recording for programmed nanoparticle assembly

Abstract

We report a novel nanomanufacturing technique that incorporates patterned arrays built entirely from Fe₃O₄ nanoparticles into a flexible and transparent polymer film. First, the nanoparticles are patterned using the enormous magnetic field gradients at the surface of commercial disk drive media, and then the resulting architecture is transferred to the surface of a polymer film by spin-coating and peeling. Since the particles are immobilized by the field gradients during the spin-coating process, the patterned array is preserved after peeling. To demonstrate the potential of this technology, we fabricate a 5 mm diameter all-nanoparticle diffraction grating capable of producing a white-light optical spectrum. We also demonstrate several extensions to this technology, where, by adding an external magnetic field during assembly, we create both periodic variations in topography, as well as a nanocomposite with two vertically and horizontally separated nanoparticle layers. As this technique leverages the nanometer resolution inherent in current magnetic recording technology, strong potential exists for low-cost nanomanufacturing of optical and electronic devices from a variety of nanomaterials with ∼10 nm resolution.

Tuning coercive force by adjusting electric potential in solution processed Co/Pt(111) and the mechanism involved

“…However, due to problems associated with increasing the storage capacity of hard disk drives, the data storage community faces the necessity of exploring and developing new concepts in attempts to increase areal density123. In recent years, extensive efforts have been devoted to exploring alternate approaches for improving the storage density of magnetic recording devices, and include two-dimensional magnetic recording (TDMR)45, heat-assisted magnetic recording (HAMR)6789, microwave-assisted magnetic recording (MAMR)1011, bit-patterned magnetic recording (BPMR)12131415, and optical switching of magnetic domains161718. For instance, a broadband near-field thermal extraction device based on hyperbolic metamaterials can significantly enhance near-field energy transfer by extracting evanescent waves with arbitrarily large lateral wave vectors6.…”

“…Near-field thermal extraction has important practical implications in HAMR68. Free-floating magnetic structures composed of in situ cross-linked magnetically assembled nanoparticles have been reported to retain their patterned shape during manipulation with external magnetic fields12 while a magnetic pattern can serve as an elementary base in magnetic recording media such as BPMR1214. By exploiting the field-confining capability as plasmonic nanoantennas, ferrimagnetic TbFeCo thin films have the potential for use in the optical switching of magnetic domains, while the importance of a chemically homogeneous sample structure is highlighted for optical switching-based recording technologies16.…”

Direct Laser Writing of Magneto-Photonic Sub-Microstructures for Prospective Applications in Biomedical Engineering

“…Structures made by magnetic nanocomposites are useful for a wide range of applications including data storage [9,10], sensors [11], actuators [12], biomedicine [13], etc. A number of synthesis and fabrication methods have been proposed to obtain desired magnetic structures, for instance, self-assembly [14,15], bio-templating [16], inkjet-printing [17], and stop-flow lithography [18].…”

Effect of structure on the magnetic anisotropy ofL10FePt nanoparticles

“…2,3 Recently demand has arisen for magnetic particles with high anisotropic energy necessary for energy-harvesting technologies 4 as well as for ultra-high-density recording media. 5 Satisfaction of this demand requires development of metal thin-film media with smaller particles, more tightly-sized distributions, and optimized compositions. 6,7 Since the mid-1930s Fe-Pt alloys of L1 0 phase have been known to exhibit high magnetocrystalline anisotropy.…”