Date of this Version
J. Mater. Chem. C, 2013, 1, 2975
Magnetophotonic crystals (MPCs) are periodic structures that are made of a magnetic material or have a magnetic defect introduced in a periodic non-magnetic matrix, and possess interesting optical and magneto-optical properties. Of particular interest are three-dimensional (3D) MPCs made of magnetic complex oxides, such as yttrium iron garnet (Y3Fe5O12, YIG) and bismuth ferrite (BiFeO3, BFO). In this paper we report for the first time the synthesis of 3D MPCs with a face-centered cubic (fcc) inverse opal structure based on these materials. The samples were prepared by a sol–gel method that involves infiltration of polystyrene colloidal crystals with liquid precursors followed by a high-temperature annealing. The developed procedure yields high-quality single-phase YIG and BFO inverse opals with high filling fractions of magnetic materials. Optical measurements were performed on large (characteristic size ~ 100µm) single crystal domains of inverse opals, and angle-dependent reflectance peaks caused by the Bragg diffraction of light in highly ordered YIG and BFO MPCs were observed. Also, since BFO has a high refractive index (>2.8) and a low extinction coefficient at λ > 550 µm, BFO MPCs with the fcc structure have a potential for the realization of a complete photonic band gap in the visible and near infrared regions.