Anomalous grazing-incidence small-angle X-ray scattering of Ga₂O₃-based nanoparticles

Abstract

Grazing-incidence small-angle X-ray scattering (GISAXS) performed at several X-ray energies in the vicinity of the absorption edge of a considered element is called anomalous GISAXS (AGISAXS). This emerging technique takes advantage of the variation of the scattering factor near an absorption edge, allowing the morphology of multi-component nanomaterials to be unraveled. The selected model system for AGISAXS simulations is mainly an In 2 O 3 layer containing Ga 2 O 3 -based nanoparticles. The transmission coefficients at the different X-ray energies near the Ga K edge are identical at one specific incident angle (near the critical angle). Hence, it could be relevant to perform AGISAXS at this incident angle in order to cancel the transmission modification as the X-ray energy changes. For buried nanoparticles, grazing-incidence effects are negligible with respect to the anomalous element-specific contribution provided that the experiments are performed at energies a few electronvolts below the absorption edge. Interestingly, AGISAXS has a clearly different intensity behavior versus X-ray energy for an embedded monodisperse spherical particle, a hole and a core-shell particle. Hence, AGISAXS can be used to unambiguously distinguish such embedded particles. Moreover, even for a dense layer of core-shell nanoparticles on a substrate, anomalous effects are much larger than grazing effects as the X-ray energy changes. Finally, it is shown that experimental anomalous scattering can be significant and can be satisfactorily simulated.

In Situ Monitoring of Scale Effects on Phase Selection and Plasmonic Shifts during the Growth of AgCu Alloy Nanostructures for Anticounterfeiting Applications

“…For the first time, we are able to deduce effective diffusion coefficients, which clearly corroborate theoretical assumptions on the phase separation process. To enhance the material contrast between metals in the alloy, future studies using anomalous GISAXS might be an option . Yet, we are able to deduce the changing composition of the different phases as a function of deposited thickness and the delayed onset of the growth of the Ag-rich phase.…”

“…To enhance the material contrast between metals in the alloy, future studies using anomalous GISAXS might be an option. 73 Yet, we are able to deduce the changing composition of the different phases as a function of deposited thickness and the delayed onset of the growth of the Ag-rich phase. The core−shell morphology clearly affects the mobility of the alloy clusters, being dominated by the Ag atoms.…”

Analysis of Homopolymer Distribution in a Polymer Blend Thin Film by Anomalous Grazing Incidence Small-Angle X-ray Scattering at the Bromine K-Edge

“…For example, Sugiyama et al analyzed the distribution of metal ions in a Nafion film using ASAXS at the copper K-edge. Moreover, the anomalous X-ray scattering technique was applied to grazing incidence geometry to study the shape, sizes, and spatial correlation of metallic nanoparticles on a substrate. − However, only few studies have investigated organic thin films using anomalous X-ray scattering techniques in the hard-X-ray regime.…”