Fe(3)O(4)-Au and Fe(2)O(3)-Au Hybrid Nanorods: Layer-by-Layer Assembly Synthesis and Their Magnetic and Optical Properties.

A layer-by-layer technique has been developed to synthesize FeOOH-Au hybrid nanorods that can be transformed into Fe(2)O(3)-Au and Fe(3)O(4)-Au hybrid nanorods via controllable annealing process. The homogenous deposition of Au nanoparticles onto the surface of FeOOH nanorods can be attributed to the strong electrostatic attraction between metal ions and polyelectrolyte-modified FeOOH nanorods. The annealing atmosphere controls the phase transformation from FeOOH-Au to Fe(3)O(4)-Au and α-Fe(2)O(3)-Au. Moreover, the magnetic and optical properties of as-synthesized Fe(2)O(3)-Au and Fe(3)O(4)-Au hybrid nanorods have been investigated.