Abstract:
To eliminate compositional and size variabilities between individual binary nanoparticles, it is
essential to control the mechanistic steps involved in nanoparticle synthesis. A common method for
synthesizing FePt nanoparticles involves the simultaneous decomposition and reduction in iron and
platinum precursors, respectively. This simultaneous nucleation and growth method yields wide
composition and size distributions. This paper describes and experimentally validates a
methodology needed to tighten composition and size distributions for this process. By engineering
the surfactant chemistry with tertiary phosphines to tightly bind the iron atoms in the iron precursor,
uniform platinum rich seeds form during the initial stages of the synthesis. A thermodynamically
preferred heterogeneous nucleation of iron atoms into these uniform platinum seeds in the
subsequent stages produces a final dispersion with uniform particle-to-particle compositions. The
paper addresses the understanding for optimizing the nucleation and growth sequences for
compositional control in FePt nanoparticles.
