Synthesis, shape control, and optical properties of hybrid Au/Fe ₃O₄ "nanoflowers"

A procedure that allows for the preparation of a range of Au/Fe ₃O₄ hybrid nanoflowers differing in the relative sizes and the numbers of ion oxide domains, was reported. The nanoflower particle were synthesized in a solution of oleylamine in I-octadecene heated to 100°C under argon and AuNP seeds were injected into this solution. High-resolution images of the composite particles confirm that the distance between two adjacent lattice planes in Fe₃O₄ domains is 4.88 Å, which is consistent with the reported value of 4.85 Å for (111) planes. It is also found that he crystallinity of the Au seeds controls the nucleation, with one iron leaf nucleated per monocrystalline domain of gold. The growth of consecutive leaves is accompanied by the red shift, broadening, and gradual extinction of the Au SPR band in the visible region.