Scanning Transmission X‐Ray Microscopy as a Novel Tool to Probe Colloidal and Photonic Crystals

Abstract Photonic crystals consisting of nano‐ to micrometer‐sized building blocks, such as multiple sorts of colloids, have recently received widespread attention. It remains a challenge, however, to adequately probe the internal crystal structure and the corresponding deformations that inhibit the proper functioning of such materials. It is shown that scanning transmission X‐ray microscopy (STXM) can directly reveal the local structure, orientations, and even deformations in polystyrene and silica colloidal crystals with 30‐nm spatial resolution. Moreover, STXM is capable of imaging a diverse range of crystals, including those that are dry and inverted, and provides novel insights complementary to information obtained by benchmark confocal fluorescence and scanning electron microscopy techniques.