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

Abstract

Patterning of L1 0 FePt nanoparticles (NPs) with high coercivity offers a promising route to develop bit-patterned media (BPM) for the next generation magnetic data recording system, but the synthesis of monodisperse FePt NPs and mass production of their nanopatterns has been a longstanding challenge. Here, highly efficient nanoimprint lithography was applied for large-scale universal patterning, which was achieved by imprinting the solution of a single-source bimetallic precursor. The rigid coplanar metallic cores and the surrounding flexible tails in the bimetallic complex permit the spontaneous molecular arrangements to form the highly ordered negative morphology replicated from the soft template. In-situ pyrolysis study was then investigated by one-pot pyrolysis of the precursor under an Ar/H 2 atmosphere, and the resultant NPs were fully characterized to identify the phase, morphology and magnetic properties. Finally, highly-ordered patterns on certain substrates were preserved perfectly after pyrolysis and could be potentially utilized in magnetic data recording media.

Nanoimprint Lithography‐Directed Self‐Assembly of Bimetallic Iron–M (M=Palladium, Platinum) Complexes for Magnetic Patterning

“…For the synthesis of Fe‐based ferromagnetic alloy nanoparticles (NPs), the weak interactions among the molecular precursors enable the formation of ordered aggregates which further ensure the uniformity of NPs . Besides providing the rich functionality, the sterically bulky pendant has also been shown not to affect the intramolecular interactions, but to favor the stacking behavior in a head‐to‐tail mode . Following this principle and our previous research work on the synthesis and patterning of FePt NPs, it would be intriguing to develop the Fc‐TPy system for bimetallic self‐assembly.…”

New insights into size-controlled reproducible synthesis of anisotropic Fe3O4 nanoparticles: the importance of the reaction environment

“…18,19 Such magnetic superstructures exhibit collective magnetic and magnetically enhanced mechanical properties which can be tailored by the shape of the NPs as well as the morphology of self-assembled superstructures. 20 In the last two decades, various approaches based on the microemulsion, 21 co-precipitation, 22 hydrothermal, 23 and thermal decomposition 10,[24][25][26][27] methods have been researched for the synthesis of anisotropic Fe 3 O 4 NPs. Among these, thermal decomposition of iron oleate in the presence of oleic acid and/or sodium oleate and octadecene has been used to synthesize Fe 3 O 4 NPs in different shapes (cubic, octapods, octahedra, plates, and rods), 11,18,28 resulting in good control over the shape and size (3-25 nm).…”

Amphiphilic bimetallic polymer as single-source precursors for the one-pot synthesis of L10-phase FePt nanoparticles

“…Currently, there are two major approaches to accomplish the goals for further patterned devices [21], one is the direct self-assembly of FePt NPs [22], and the other is preparing ordered patterns from the processing of the precursors with a subsequent in-situ synthesis of FePt NPs, which often refers to lithographic patterning [23,24] or self-assembly of the precursors. On this basis, our group had been devoted ourselves to expanding the lithographic route for the mass production of ferromagnetic patterns, and the detailed study from solution-processable metallopolymers to hemiphasmidic small molecule precursors and the various processing means such as nanoimprint lithography further promoted the developments of patterned FePt NPs [1,25,26]. Besides, tridentate coplanar structure of platinum complexes with the functionality of ferrocene were also investigated in our previous reports [14,25], in which the strong Pt … Pt interactions and π-π stacking played an important roles in affecting the formation of FePt NPs.…”