Metallopolymer precursors to L1₀-CoPt nanoparticles: synthesis, characterization, nanopatterning and potential application

Abstract

Ferromagnetic (L1₀ phase) CoPt alloy nanoparticles (NPs) with extremely high magnetocrystalline anisotropy are promising candidates for the next generation of ultrahigh-density data storage systems. It is a challenge to generate L1₀ CoPt NPs with high coercivity, controllable size, and a narrow size distribution. We report here the fabrication of L1₀CoPt NPs by employing a heterobimetallic CoPt-containing polymer as a single-source precursor. The average size of the resulting L1₀ CoPt NPs is 3.4 nm with a reasonably narrow size standard deviation of 0.58 nm. The coercivity of L1₀ CoPt NPs is 0.54 T which is suitable for practical application. We also fabricated the L1₀ CoPt NP-based nanoline and nanodot arrays through nanoimprinting the polymer blend of CoPt-containing metallopolymer and polystyrene followed by pyrolysis. The successful transfer of the pre-defined patterns of the stamps onto the surface of the polymer blend implies that this material holds great application potential as a data storage medium.