Characterization of Medium-range Order in Self-Assembled Organic-inorganic Hybrid by Fluctuation X-ray Microscopy

2006 ◽  
Vol 960 ◽  
Author(s):  
Lixin Fan ◽  
David Paterson ◽  
Ian McNulty ◽  
M. M. J. Treacy ◽  
Dushyant Kumar ◽  
...  
Keyword(s):  
Self Assembly ◽  
Sol Gel ◽  
Range Order ◽  
Inorganic Materials ◽  
Medium Range Order ◽  
X Ray ◽  
Sol Gel Process ◽  
Medium Range ◽  
Self Assembled

ABSTRACTThe control of formation and ordering of self assembled nanostructures, with medium- to long-range order, is a challenge that limits advances in many fields of nanotechnology. We have developed a technique, which we call fluctuation x-ray microscopy, that offers quantitative insight into medium-range correlations in disordered materials at nanometer- and larger-length scales. We examined the influence of sol-gel process variables on medium range order in PI-b-PEO/ aluminosilicate bulk using this technique. The nano-structuring of inorganic materials was directed by polymer self-assembly. The medium range correlation between the nanostructures in two hybrids was quantitatively examined and compared.

Medium-Range Order of Amorphous Silicon Germanium Alloys: Small-Angle X-Ray Scattering Study

1989 ◽  
Vol 28 (Part 2, No. 7) ◽  
pp. L1092-L1095 ◽  
Author(s):  
Shin-ichi Muramatsu ◽  
Toshikazu Shimada ◽  
Hiroshi Kajiyama ◽  
Kazufumi Azuma ◽  
Takeshi Watanabe ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Small Angle ◽  
Silicon Germanium ◽  
Range Order ◽  
Medium Range Order ◽  
X Ray ◽  
X Ray Scattering ◽  
Medium Range ◽  
Scattering Study ◽  
Amorphous Silicon Germanium

scholarly journals Temperature dependence of amorphous magnesium carbonate structure studied by PDF and XAFS analyses

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Gen-ichiro Yamamoto ◽  
Atsushi Kyono ◽  
Satoru Okada
Keyword(s):  
Temperature Dependence ◽  
Three Dimensional ◽  
Magnesium Carbonate ◽  
Range Order ◽  
Edge Structure ◽  
Medium Range Order ◽  
X Ray ◽  
Medium Range ◽  
Mineral Trapping ◽  
X Ray Absorption

AbstractMineral trapping through the precipitation of carbonate minerals is a potential approach to reduce CO2 accumulation in the atmosphere. The temperature dependence of amorphous magnesium carbonate (AMC), a precursor of crystalline magnesium carbonate hydrates, was investigated using synchrotron X-ray scattering experiments with atomic pair distribution function (PDF) and X-ray absorption fine structure analysis. PDF analysis revealed that there were no substantial structural differences among the AMC samples synthesized at 20, 60, and 80 °C. In addition, the medium-range order of all three AMC samples was very similar to that of hydromagnesite. Stirring in aqueous solution at room temperature caused the AMC sample to hydrate immediately and form a three-dimensional hydrogen-bonding network. Consequently, it crystallized with the long-range structural order of nesquehonite. The Mg K-edge X-ray absorption near-edge structure spectrum of AMC prepared at 20 °C was very similar to that of nesquehonite, implying that the electronic structure and coordination geometry of Mg atoms in AMC synthesized at 20 °C are highly similar to those in nesquehonite. Therefore, the short-range order (coordination environment) around the Mg atoms was slightly modified with temperature, but the medium-range order of AMC remained unchanged between 20 and 80 °C.

scholarly journals Sol-Gel Template Synthesis and Characterization of Lu2O3:Eu3+ Nanowire Arrays

Micromachines ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 601
Author(s):  
Yahua Hu ◽  
Mu Gu ◽  
Xiaolin Liu ◽  
Juannan Zhang ◽  
Shiming Huang ◽  
...  
Keyword(s):  
Sol Gel ◽  
Nanowire Arrays ◽  
X Ray Diffraction ◽  
Aao Template ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Sol Gel Process ◽  
Optical Luminescence ◽  
Uniform Diameter

Uniform Lu2O3:Eu3+ nanowire arrays were successfully prepared by the sol-gel process using anodic aluminum oxide (AAO) templates. The as-synthesized nanowires are homogeneous, highly ordered, and dense and have a uniform diameter of ~300 nm defined by the AAO templates. The X-ray diffraction and selected area electron diffraction results show that the Lu2O3:Eu3+ nanowires have a polycrystalline cubic structure, and the crystallite size of the Lu2O3:Eu3+ nanowires is confined by the AAO template. The nanowires within the AAO template showed good photoluminescence and X-ray-excited optical luminescence performances for Lu2O3:Eu3+. The emission peaks were attributed to the 5D0 → 7FJ transitions of Eu3+ (J = 0, 1, 2, 3).

Sol-gel derived Ba(Mg1/3Ta2/3)O3 thin films: Preparation and structure

1997 ◽  
Vol 12 (3) ◽  
pp. 596-599 ◽  
Author(s):  
Ji Zhou ◽  
Qing-Xin Su ◽  
K. M. Moulding ◽  
D. J. Barber
Keyword(s):  
Thin Films ◽  
Annealing Temperature ◽  
Volume Fraction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Sol Gel Process ◽  
Small Grains

Ba(Mg1/3Ta2/3)O3 thin films were prepared by a sol-gel process involving the reaction of barium isopropoxide, tantalum ethoxide, and magnesium acetate in 2-methoxyethanol and subsequently hydrolysis, spin-coating, and heat treatment. Transmission electron microscopy, x-ray diffraction, and Raman spectroscopy were used for the characterization of the thin films. It was shown that the thin films tend to crystallize with small grains sized below 100 nm. Crystalline phase with cubic (disordered) perovskite structure was formed in the samples annealed at a very low temperature (below 500 °C), and well-crystallized thin films were obtained at 700 °C. Although disordered perovskite is dominant in the thin films annealed below 1000 °C, a low volume fraction of 1 : 2 ordering domains was found in the samples and grows with an increase of annealing temperature.

Synthesis and Characterization of Cellular SiO2 Materials by Foaming Sol Gels

1990 ◽  
Vol 207 ◽  
Author(s):  
Josephine Covino ◽  
Allen P. Gehris
Keyword(s):  
Sol Gel ◽  
Optical Characterization ◽  
Viscosity Change ◽  
Density Measurements ◽  
X Ray ◽  
X Ray Crystallography ◽  
Foaming Process ◽  
Sol Gel Process ◽  
Porous Oxides

AbstractA variety of cellular SiO2 materials have been synthesized using a foaming sol-gel process and their properties have been characterized. The process uses the rapid viscosity change during gelation to stabilize the structure of a foamed silica sol. It was found that the properties of these cellular materials are determined by method used. For example, the porosity and strength of these porous oxides depend on method of agitation and addition of Freon during the foaming process.Density measurements, viscosity measurements as a function of pH, optical characterization, x-ray crystallography, ultimate compressive strength, dielectric constant measurements and thermal diffusivity were used to characterize these porous SiO2 materials. This paper will discuss the synthetic processes used to develop the porous silicas and properties of these materials.

scholarly journals Using coherent X-ray ptychography to probe medium-range order

2013 ◽  
Vol 21 (23) ◽  
pp. 28019 ◽  
Author(s):  
A. T. J. Torrance ◽  
B. Abbey ◽  
C. T. Putkunz ◽  
D. Pelliccia ◽  
E. Balaur ◽  
...  
Keyword(s):  
Range Order ◽  
Medium Range Order ◽  
X Ray ◽  
Medium Range

scholarly journals Structural and Magneto-Optical Characterization of La, Nd: Y2O3 Powders Obtained via a Modified EDTA Sol–Gel Process and HIP-Treated Ceramics

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4928
Author(s):  
Andrzej Kruk
Keyword(s):  
Sol Gel ◽  
Hot Isostatic Pressing ◽  
Rare Earth Ions ◽  
X Ray Diffraction ◽  
Thermal Dependence ◽  
Nanosized Powders ◽  
Verdet Constant ◽  
X Ray ◽  
Sol Gel Process

In this study, pure Y2O3, La0.1Y1.9O3 and La0.1Nd0.12Y1.78O3 nanosized powders were successfully synthesized by a modified sol–gel method. Pure and rare-earth ions doped yttria powders were characterized by X-ray diffraction, scanning electron microscopy and Brunauer–Emmett–Teller methods. The powders were sintered by the hot isostatic pressing process. The highest in-line transmittance of 56% was obtained at 800 nm and increased in the IR region. The influence of the lanthanum and neodymium ions on the physicochemical properties of yttria were discussed. The La-Nd-doped material exhibited a Verdet constant over 4000 deg/T·m at 400 nm and low thermal dependence. An interesting evolution of the Verdet constant across the absorption band with high resolution was studied. A study of the optical and magneto-optical properties of yttria doped with Nd3+ and La3+ is discussed in this paper.

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