Characterization of Photonic Colloidal Single Crystals by Microradian X‐ray Diffraction

Abstract

Close‐packed and non‐close‐packed colloidal photonic crystals of silica spheres have been imaged in real space to reveal their 3D structure. Although the lattice spacings are of the order of a micrometer, these crystals can also be characterized in reciprocal space using small‐angle X‐ray scattering (see figure). After infiltration with silicon (see inset), the internal 3D structure of these photonic crystals can only be probed using X‐ray scattering.

Periodic order and defects in Ni-based inverse opal-like crystals on the mesoscopic and atomic scale

“…The obtained ratio between the twin components does not demonstrate a clear dependence on the number of layers. So, the ratio is 1:1 for Ni 3,5 samples, 4:5 for Ni 8 and Ni 26 samples, and 2:1 for the Ni 17 sample as one can estimate from Fig. 5.…”

“…(8) divided by the lattice parameter at that temperature was averaged over the same temperature range as in Ref. [54], i.e., 173-298 K. In particular, the obtained CT E value for the samples with a large number of layers (Ni 17 and Ni 26 ) is (1.33 ± 0.05) × 10 −5 K −1 , which agrees with the value for Ni thin film presented in Ref. [54] ((1.37 ± 0.04) × 10 −5 K −1 ) and higher than that for bulk Ni (1.24 × 10 −5 K −1 ).…”

“…To study the IOLCs we used the same microradian setup as in [25,26] at the Dutch-Belgian bending magnet BM26 DUBBLE beamline [27] at the European Synchrotron Radiation Facility (ESRF, Grenoble, France). An x-ray beam with photon energy of 13 keV (wavelength λ = 0.95Å, bandpass λ/λ = 2 × 10 −4 , size at the sample 0.5 × 0.5mm 2 ) was focused with compound refractive lenses [28] onto the phosphor screen of a two-dimensional detector (Photonic Science CCD camera, 4000 × 2700 pixels of 9 μm 2 ) located at 8 meters behind the sample.…”

Quantifying disorder in colloidal films spin-coated onto patterned substrates

“…One barrier to attempt at improving crystallinity by varying one of the many control parameters is the absence of reliable, quantitative measures of order in relatively poorly ordered colloidal films. Reciprocal-space methods, e.g., using small-angle and ultrasmall-angle scattering [32,33], are the standard for characterizing crystalline structures; however, spatial resolution is important both for identifying subtle differences in disordered structures, as well as for following the kinetics of crystallization. Real-space methods such as those discussed here can also be used in tandem with new developments in coherent x-ray diffractive imaging [34].…”

Towards High-Resolution X-ray Microscopy on Mesoscopic Structures

“…The first family of techniques was exclusively limited to surface imaging, namely to scanning electron microscopy (SEM) and a replica-technique variety of transmission electron microscopy (TEM) [1][2][3]. Diffraction methodsvisible light diffraction and small-angle x-ray scattering-provide invaluable information on the volume-specific structure, but mainly on the average one [4][5][6]. In the best case, a statistical description mimicking the reality can be supplied, but not the specific structure realization.…”