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 L10 CoPt 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.

A molecular approach to magnetic metallic nanostructures from metallopolymer precursors

“…7 Similarly, L10 CoPt NPs have also been synthesized by one-step decomposition of heterobimetallic CoPt-containing metallopolymer (P9) or blend of Co-containing and Pt-containing homopolymers P28 and P17. 22,38 The largest coercivity of the as-prepared L10 CoPt NPs is 0.54 T at 300 K.…”

“…are two porphyrin-based FePt-containing and CoPt-containing metallopolymers, which are synthesized by coupling of the diethynyl Fe III -porphyrin or diethynyl 21,22 Usually, these FePt-containing metallopolymers were purified through repeated precipitation in a minimum volume of dichloromethane from methanol for several times to remove away any inorganic catalysts and the low-molecular-weight species. Their structures and thermal properties can be characterized by NMR, IR and TGA, etc.…”

“…The use of metalloporphyrin templates toward the preparation of other metal alloy NPs is also worthy of study. 21,22 It is noteworthy that the application of magnetic NPs in biomedicine is very intriguing, which has already developed to be a hot spot in the multidisciplinary research of nanomaterials, chemistry, biology and medicine.…”

Physical process-aided fabrication of periodic Au–M (M = Ag, Cu, Ag–Cu) alloyed nanoparticle arrays with tunable localized surface plasmon resonance and diffraction peaks

“…For now, noble metal alloyed NPs are fabricated mainly using chemical reduction method in solution (also called wetchemical syntheses). [12][13][14][15] For example, Swihart's group synthesized Au-Ag alloyed NPs by mixing metal precursors and surfactants in organic solvent, and further heating together. 16 The LSPR peak of the Au-Ag alloyed NPs in their report could be tuned by varying the precursor or the added surfactants composition.…”

Lithographic patterning of ferromagnetic FePt nanoparticles from a single-source bimetallic precursor containing hemiphasmidic structure for magnetic data recording media

“…Also, various attempts have been made to directly prepare the L1 0 FePt NPs by a one-step approach [22], and some approaches of avoiding particle sintering during post-annealing were developed, such as by lowering the transformation temperature from facecentered cubic (fcc) phase to fct phase [23] or mixing the sources with finely grounded NaCl to protect NPs from agglomeration [24,25]. Recently, our group has developed an alternative method for synthesizing L1 0 FePt NPs with high dispersity by the one-step pyrolysis, which relied on the intelligent design of some bimetallic precursors [26][27][28][29][30]. Such method can produce fct phase NPs without further thermal annealing and allow their patterning on a large scale easily by lithographic methods [6][7][8].…”