Band-Gap-Controllable Photonic Crystals Consisting of Magnetic Nanocrystal Clusters in a Solidified Polymer Matrix

Colloidal photonic crystals (CPhCs) consisting of iron oxide magnetic spheres possess high lattice tunability but are generally unstable and difficult to manage in liquid form. We solve the problem by introducing the colloidal spheres into a resin system, which can freeze three-dimensional (3D) patterns by photopolymerization. Robust solid-form CPhCs with various structural colors were, therefore, achieved. The frozen 3D patterns would,permit not only a systematic exploration on self-assembling dynamics, colloidal crystallography, and PhC physics but also may pave a new application avenue if a solid, but still soft, PhC is shaped or sliced.