IsGISAXS: a program for grazing-incidence small-angle X-ray scattering analysis of supported islands

This paper describes a Fortran program,IsGISAXS, for the simulation and analysis of grazing-incidence small-angle X-ray scattering (GISAXS) of islands supported on a substrate. As is usual in small-angle scattering of particles, the scattering cross section is expressed in terms of an island form factor and interference function. However, the emphasis is placed on the specificity of the grazing-incidence geometry, in particular in the evaluation of the island form factor in the distorted-wave Born approximation. A library of simple geometrical shapes is available. A full account of size and possible shape distributions is given in the decoupling approximation, where sizes and positions are not correlated, and in the local monodisperse approximation. Two types of island repartitions on the substrate are considered: disordered systems characterized by their particle–particle pair correlation functions, and bidimensional crystalline or paracrystalline systems of particles.

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Small angle X-Ray Scattering in Grazing Incidence Geometry

Encyclopedia of Nanotechnology ◽

10.1007/978-90-481-9751-4_100769 ◽

2012 ◽

pp. 2435-2435

Author(s):

Yimei Zhu ◽

Hiromi Inada ◽

Achim Hartschuh ◽

Li Shi ◽

Ada Della Pia ◽

...

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

Incidence Geometry ◽

X Ray ◽

X Ray Scattering ◽

Grazing Incidence Geometry ◽

Ray Scattering

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Classification of grazing-incidence small-angle X-ray scattering patterns by convolutional neural network

Journal of Synchrotron Radiation ◽

10.1107/s1600577520005767 ◽

2020 ◽

Vol 27 (4) ◽

pp. 1069-1073

Author(s):

Hiroyuki Ikemoto ◽

Kazushi Yamamoto ◽

Hideaki Touyama ◽

Daisuke Yamashita ◽

Masataka Nakamura ◽

...

Keyword(s):

Neural Network ◽

Convolutional Neural Network ◽

Small Angle ◽

Pair Correlation ◽

Grazing Incidence ◽

X Ray ◽

X Ray Scattering ◽

Nanoscale Structure ◽

Ray Scattering

Grazing-incidence small-angle X-ray scattering (GISAXS) patterns have multiple superimposed contributions from the shape of the nanoscale structure, the coupling between the particles, the partial pair correlation, and the layer geometry. Therefore, it is not easy to identify the model manually from the huge amounts of combinations. The convolutional neural network (CNN), which is one of the artificial neural networks, can find regularities to classify patterns from large amounts of combinations. CNN was applied to classify GISAXS patterns, focusing on the shape of the nanoparticles. The network found regularities from the GISAXS patterns and showed a success rate of about 90% for the classification. This method can efficiently classify a large amount of experimental GISAXS patterns according to a set of model shapes and their combinations.

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Small-angle X-ray scattering from GaN nanowires on Si(111): facet truncation rods, facet roughness and Porod's law

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s205327332001548x ◽

2021 ◽

Vol 77 (1) ◽

pp. 42-53

Author(s):

Vladimir M. Kaganer ◽

Oleg V. Konovalov ◽

Sergio Fernández-Garrido

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

Incidence Geometry ◽

Root Mean Square Roughness ◽

Scattering Intensity ◽

X Ray ◽

Gan Nanowires ◽

X Ray Scattering ◽

Orientational Distribution ◽

Ray Scattering

Small-angle X-ray scattering from GaN nanowires grown on Si(111) is measured in the grazing-incidence geometry and modelled by means of a Monte Carlo simulation that takes into account the orientational distribution of the faceted nanowires and the roughness of their side facets. It is found that the scattering intensity at large wavevectors does not follow Porod's law I(q) ∝ q −4. The intensity depends on the orientation of the side facets with respect to the incident X-ray beam. It is maximum when the scattering vector is directed along a facet normal, reminiscent of surface truncation rod scattering. At large wavevectors q, the scattering intensity is reduced by surface roughness. A root-mean-square roughness of 0.9 nm, which is the height of just 3–4 atomic steps per micrometre-long facet, already gives rise to a strong intensity reduction.

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Small Angle X-Ray Scattering in Grazing Incidence Geometry

Encyclopedia of Nanotechnology ◽

10.1007/978-94-017-9780-1_101033 ◽

2016 ◽

pp. 3719-3719

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

Incidence Geometry ◽

X Ray ◽

X Ray Scattering ◽

Grazing Incidence Geometry ◽

Ray Scattering

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Grazing Incidence Small Angle X-Ray Scattering Study on Low Dielectric Thin Films

MRS Proceedings ◽

10.1557/proc-612-d5.23.1 ◽

2000 ◽

Vol 612 ◽

Cited By ~ 5

Author(s):

C.-H. Hsu ◽

Hsin-Yi Lee ◽

K.S. Liang ◽

U-Ser Jeng ◽

D. Windover ◽

...

Keyword(s):

Thin Films ◽

Small Angle ◽

Grazing Incidence ◽

Dielectric Materials ◽

Incidence Geometry ◽

Silica Xerogel ◽

Saxs Data ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

AbstractHighly porous silica films with pore size in the nanometer scale are being extensively studied as potential candidates for interlevel dielectrics. Because these dielectric materials appear in the form of thin films with a thickness of only several thousand Angstroms, conventional techniques are difficult to be readily applied to study their structure and porosity. We employed small angle scattering in the grazing incidence geometry in this study. Using high resolution xray beamline with synchrotron radiation source, we demonstrate that the small angle x-ray scatteirng (SAXS) data of the porous films can be obtained. The structure of sol-gel derived silica - xerogel films on silicon substrate studied by specular reflectivity and grazing incidence small angle x-ray scattering (GISAXS) will be presented.

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Study of quasi-two- and three-dimensional ordered porous structures by means of small-angle X-ray scattering in the grazing incidence geometry

Physics of the Solid State ◽

10.1134/s1063783417120137 ◽

2017 ◽

Vol 59 (12) ◽

pp. 2464-2475 ◽

Cited By ~ 2

Author(s):

I. S. Dubitskiy ◽

N. A. Grigoryeva ◽

A. A. Mistonov ◽

G. A. Valkovskiy ◽

N. A. Sapoletova ◽

...

Keyword(s):

Small Angle ◽

Three Dimensional ◽

Grazing Incidence ◽

Incidence Geometry ◽

Porous Structures ◽

X Ray ◽

X Ray Scattering ◽

Grazing Incidence Geometry ◽

Ordered Porous ◽

Ray Scattering

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Grazing incidence small angle X-ray scattering from nanoparticles: beyond classical analysis approximations

Acta Crystallographica Section A Foundations of Crystallography ◽

10.1107/s0108767305082607 ◽

2005 ◽

Vol 61 (a1) ◽

pp. c411-c411

Author(s):

R. Lazzari ◽

G. Renaud ◽

F. Leroy

Keyword(s):

Small Angle ◽

Grazing Incidence ◽

Classical Analysis ◽

X Ray ◽

X Ray Scattering ◽

Ray Scattering

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Osmotic shrinkage of sterically stabilized liposomes as revealed by time-resolved small-angle X-ray scattering

Journal of Applied Crystallography ◽

10.1107/s1600576713030513 ◽

2014 ◽

Vol 47 (1) ◽

pp. 35-40 ◽

Cited By ~ 10

Author(s):

Zoltán Varga ◽

András Wacha ◽

Attila Bóta

Keyword(s):

Form Factor ◽

Small Angle ◽

Freeze Fracture ◽

Initial Step ◽

Time Resolved ◽

X Ray ◽

X Ray Scattering ◽

Sterically Stabilized Liposomes ◽

Liposome Size ◽

Ray Scattering

Time-resolved synchrotron small-angle X-ray scattering (SAXS) was used to study the structural changes during the osmotic shrinkage of a pharmacologically relevant liposomal drug delivery system. Sterically stabilized liposomes (SSLs) with a diameter of 100 nm and composed of hydrogenated soy phosphocholine, cholesterol and distearoyl-phosphoethanolamine-PEG 2000 prepared in a salt-free buffer were mixed with a buffered 0.3 MNaCl solution using a stopped flow apparatus. The changes in the liposome size and the bilayer structure were followed by using SAXS with a time resolution of 20 ms. A linear decrease in liposome size is observed during the first ∼4 s of the osmotic shrinkage, which reveals a water permeability value of 0.215 (15) µm s−1. The change in the size of the liposomes upon the osmotic shrinkage is also confirmed by dynamic light scattering. After this initial step, broad correlation peaks appear on the SAXS curves in theqrange of the bilayer form factor, which indicates the formation of bi- or oligolamellar structures. Freeze-fracture combined with transmission electron microscopy revealed that lens-shaped liposomes are formed during the shrinkage, which account for the appearance of the quasi-Bragg peaks superimposed on the bilayer form factor. On the basis of these observations, it is proposed that the osmotic shrinkage of SSLs is a two-step process: in the initial step, the liposome shrinks in size, while the area/lipid adapts to the decreased surface area, which is then followed by the deformation of the spherical liposomes into lens-shaped vesicles.

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