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

Amphiphilic polymers have attracted extensive research attention in constructing various nanostructures by self-assembly. Here we designed and synthesized two amphiphilic bimetallic polymers with different length of the tails P1 and P2, in which Fe,Pt-containing conjugated complex acted as the hydrophobic block and hydrophilic poly(ethylene glycol)(PEG)was bonded to the bimetallic core as the flexible tails. P1 and P2 were used as the single-source precursors to prepare FePt nanoparticles (NPs)by one-pot pyrolysis. The resultant NPs were fully characterized and had a chemically ordered face-centered tetragonal (fct)phase with high crystallinity. The size of NPs pyrolyzed from P1 and P2 was 24.7 and 8.2 nm with the relative coercivity of 9.6 and 1.3 kOe, respectively. The difference was preliminarily explained by the discrepancy of their degrees of crystallinity, and also analyzed by the precursors’ structural effect. The amphiphilic design showed a good potential in preparing monodisperse ferromagnetic FePt NPs, and the possible favorable properties of self-assembly might provide a bright venue for future magnetic recording media.