Preparation of Quantum-Sized Semiconductor Sulfide-Doped Gels

1992 ◽  
Vol 272 ◽  
Author(s):  
T. Gacoin ◽  
J.P. Boilot ◽  
F. Chaput ◽  
A. Lecomte
Keyword(s):  
Optical Spectroscopy ◽  
Small Angle ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Direct Precipitation ◽  
Semiconductor Particles ◽  
Optically Transparent ◽  
Thiolate Complexes

ABSTRACTUltrasmall semiconductor particles (CdS, ZnS and PbS) are produced either by direct precipitation, γ-radiolysis or in mimetic membranes. A pure cluster powder is then prepared from a chemical capping reaction. The capping of the cluster surface by thiolate complexes permits the separation of aggregates without fusion. These capped clusters can be dispersed in different solvents such as sol-gel precursors allowing to prepare dense and optically transparent xerogels with semiconductor clusters grafted on oxide polymers. The nanocrystallites are characterized by X-ray diffraction, small-angle X-ray scattering and optical spectroscopy.

Time-resolved isothermal crystallization of absorbable PGA-co-PLA copolymer by synchrotron small-angle X-ray scattering and wide-angle X-ray diffraction

Polymer ◽  
2001 ◽  
Vol 42 (21) ◽  
pp. 8965-8973 ◽  
Author(s):  
Zhi-Gang Wang ◽  
Xuehui Wang ◽  
Benjamin S. Hsiao ◽  
Saša Andjelić ◽  
Dennis Jamiolkowski ◽  
...  
Keyword(s):  
Small Angle ◽  
Isothermal Crystallization ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

A high-throughput assembly of beam-shaping channel-cut monochromators for laboratory high-resolution X-ray diffraction and small-angle X-ray scattering experiments

2021 ◽  
Vol 54 (3) ◽  
Author(s):  
Peter Nadazdy ◽  
Jakub Hagara ◽  
Petr Mikulik ◽  
Zdenko Zaprazny ◽  
Dusan Korytar ◽  
...  
Keyword(s):  
High Resolution ◽  
Small Angle ◽  
Photon Flux ◽  
Photon Flux Density ◽  
X Ray Diffraction ◽  
High Beam ◽  
X Ray ◽  
X Ray Scattering ◽  
Beam Collimation ◽  
Ray Scattering

A four-bounce monochromator assembly composed of Ge(111) and Ge(220) monolithic channel-cut monochromators with V-shaped channels in a quasi-dispersive configuration is presented. The assembly provides an optimal design in terms of the highest transmittance and photon flux density per detector pixel while maintaining high beam collimation. A monochromator assembly optimized for the highest recorded intensity per detector pixel of a linear detector placed 2.5 m behind the assembly was realized and tested by high-resolution X-ray diffraction and small-angle X-ray scattering measurements using a microfocus X-ray source. Conventional symmetric and asymmetric Ge(220) Bartels monochromators were similarly tested and the results were compared. The new assembly provides a transmittance that is an order of magnitude higher and 2.5 times higher than those provided by the symmetric and asymmetric Bartels monochromators, respectively, while the output beam divergence is twice that of the asymmetric Bartels monochromator. These results demonstrate the advantage of the proposed monochromator assembly in cases where the resolution can be partially sacrificed in favour of higher transmittance while still maintaining high beam collimation. Weakly scattering samples such as nanostructures are an example. A general advantage of the new monochromator is a significant reduction in the exposure time required to collect usable experimental data. A comparison of the theoretical and experimental results also reveals the current limitations of the technology of polishing hard-to-reach surfaces in X-ray crystal optics.

Characterizing nanoparticles with a laboratory diffractometer: from small-angle to total X-ray scattering

2014 ◽  
Vol 29 (S1) ◽  
pp. S47-S53 ◽  
Author(s):  
Marco Sommariva ◽  
Milen Gateshki ◽  
Jan-André Gertenbach ◽  
Joerg Bolze ◽  
Uwe König ◽  
...  
Keyword(s):  
Small Angle ◽  
Structural Features ◽  
Bragg Diffraction ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Transmission Electron ◽  
Pdf Analysis ◽  
Comprehensive Picture ◽  
Ray Scattering

X-ray diffraction and scattering on a single multipurpose X-ray platform have been used to probe the structure, composition, and thermal behavior of TiO2 nanoparticles ranging in size from 1 to 10 nm. Ambient and non-ambient Bragg diffraction, small-angle X-ray scattering (SAXS), as well as total scattering and pair-distribution function (PDF) analysis are combined to obtain a comprehensive picture of the samples. At these ultrasmall particle-size dimensions, SAXS and PDF prove powerful in distinguishing the salient features of the materials, in particular the size distribution of the primary particles (SAXS) and the identification of the TiO2 polymorphs (PDF). Structural features determined by X-ray scattering techniques are corroborated by high-resolution transmission electron microscopy. The elemental make-up of the materials has been measured using X-ray fluorescence spectrometry and energy-dispersive X-ray analysis.

Scatterless hybrid metal–single-crystal slit for small-angle X-ray scattering and high-resolution X-ray diffraction

2008 ◽  
Vol 41 (6) ◽  
pp. 1134-1139 ◽  
Author(s):  
Youli Li ◽  
Roy Beck ◽  
Tuo Huang ◽  
Myung Chul Choi ◽  
Morito Divinagracia
Keyword(s):  
High Resolution ◽  
Single Crystal ◽  
Small Angle ◽  
Incident Beam ◽  
Single Crystal Substrate ◽  
X Ray Diffraction ◽  
Metal Base ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

A simple hybrid design has been developed to produce practically scatterless aperture slits for small-angle X-ray scattering and high-resolution X-ray diffraction. The hybrid slit consists of a rectangular single-crystal substrate (e.g.Si or Ge) bonded to a high-density metal base with a large taper angle (> 10°). The beam-defining single-crystal tip is oriented far from any Bragg peak position with respect to the incident beam and hence produces none of the slit scattering commonly associated with conventional metal slits. It has been demonstrated that the incorporation of the scatterless slits leads to a much simplified design in small-angle X-ray scattering instruments employing only one or two apertures, with dramatically increased intensity (a threefold increase observed in the test setup) and improved low-angle resolution.

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