Rapid evaporation-induced self-assembly of three-dimensional photonic crystals using Fe3O4@C magnetic nanocomposites

Abstract

Three-dimensional photonic crystals with structural regularity and metallic luster have been prepared via a rapid evaporation-induced self-assembly process using Fe₃O₄@C magnetic nanocomposites (MNCPs) as building blocks. The MNCPs self-assembled into one-dimensional nanochains during solvothermal synthesis. Then the nanochains directly stacked into three-dimensional photonic structures induced by evaporation which greatly accelerated the self-assembly process within 2.5 hours. Effects of three important parameters including temperature, dispersion concentration and the solvent type on evaporation-induced self-assembly have been investigated. It was proved that these factors have a significant impact on structural regularity and lustrousness of the resulting photonic crystals. Meanwhile, photonic crystals with different diffraction colors were obtained by controlling the particle size of MNCPs through adjusting the solvothermal reaction temperature.