Synthesis and characterization of BaSn(OH)6 and BaSnO3 acicular particles

2003 ◽  
Vol 18 (3) ◽  
pp. 560-566 ◽  
Author(s):  
M. T. Buscaglia ◽  
M. Leoni ◽  
M. Viviani ◽  
V. Buscaglia ◽  
A. Martinelli ◽  
...  
Keyword(s):  
Reference Value ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
20 Nm ◽  
Continuous Weight ◽  
Perovskite Lattice ◽  
Proton Defects ◽  
Continuous Weight Loss

The synthesis of BaSn(OH)6 acicular crystals by precipitation at 100 °C from aqueous solutions and their transformation in the perovskitelike compound BaSnO3 was investigated. Single acicular crystals 100–200 μm in length were obtained from a 0.05M solution, whereas bundlelike aggregates of 20–40 μm were precipitated from 0.2–0.6 M solutions. The x-ray diffraction pattern of barium hexahydroxostannate was indexed according to monoclinic symmetry with cell parameters a = 11.029 ± 0.002 Å, b = 6.340 ± 0.001 Å, c = 10.563 ± 0.001 Å = 128.51 ± 0.01°, α = γ = 90°. The BaSn(OH)6 particles decomposed to BaSnO3 and water at approximately 270 °C and the original morphology was retained. The resulting product had specific surface area up to 30–40 m2/g and consisted of 10–20 nm crystallites. The larger unit cell edge in comparison to the reference value and the continuous weight loss up to 1200 °C indicate that water is not completely released during decomposition and a substantial amount of proton defects (up to 0.4 mol per mole of BaSnO3) is incorporated in the perovskite lattice as OH− groups. Normal crystallographic properties of BaSnO3 are restored only after calcination at 1300 °C.

scholarly journals Crystallization, optimization and preliminary X-ray characterization of a metal-dependent PI-PLC fromStreptomyces antibioticus

2012 ◽  
Vol 68 (11) ◽  
pp. 1378-1386 ◽  
Author(s):  
Michael R. Jackson ◽  
Thomas L. Selby
Keyword(s):  
X Ray Diffraction ◽  
Hanging Drop ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Streptomyces Antibioticus ◽  
Cell Parameters ◽  
Heavy Atoms ◽  
Hanging Drop Method

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) fromStreptomyces antibioticushas been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space groupP222, with unit-cell parametersa= 41.26,b= 51.86,c = 154.78 Å. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 Å resolution.

SYNTHESIS AND CHARACTERIZATION OF ZnO NANORODS AND NANOWIRES USING PVP AS CAPPING

2009 ◽  
Vol 08 (03) ◽  
pp. 285-287 ◽  
Author(s):  
M. ESKANDARI ◽  
V. AHMADI ◽  
Sh. AHMADI
Keyword(s):  
Solution Method ◽  
Zno Nanorods ◽  
Green Emission ◽  
Zno Nanowires ◽  
X Ray Diffraction ◽  
X Ray ◽  
Chemical Solution Method ◽  
Air Atmosphere ◽  
20 Nm

In this study, ZnO nanowires are synthesized via ZnO nanorods at low temperature by using zinc acetate dehydrate and polyvinylpyrrolidone as precursor and capping, respectively. We use chemical solution method for synthesis of ZnO nanowires. Samples are characterized by means of scanning electron microscopy and X-ray diffraction. First, the nanorods are prepared at 300°C temperature, and then they are put into the furnace under air atmosphere at 450°C for 2 h. It is observed that nanowires with 20 nm diameter are produced. Photoluminescence spectra of nanorods and nanowires are compared. It shows that intensity of ultraviolet peak in the nanowires decreases but in contrast the intensity of green emission part increases. This is because, the surface effects such as oxygen vacancies increase in the structures of ZnO .

scholarly journals Growth and Characterization of Pure and Doped L-Alanine Tartrate Single Crystals

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
K. Rajesh ◽  
B. Milton Boaz ◽  
P. Praveen Kumar
Keyword(s):  
Single Crystals ◽  
Vickers Microhardness ◽  
Diffraction Method ◽  
Dielectric Studies ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Single crystals of pure and Lanthanum doped L-Alanine Tartrate were grown by slow evaporation method. The cell parameters were determined using single crystal X-ray diffraction method. To improve the physical properties of the LAT crystal, Lanthanum dopant was added by 2 mol%. ICP studies confirm the presence of Lanthanum in the grown LAT crystal. Transparency range of the crystal was determined using UV-VIS-NIR spectrophotometer. The functional groups of pure and doped LAT crystals were analyzed by FT-IR spectroscopy. Using Vickers microhardness tester, mechanical strength of the material was found. Dielectric studies of pure and doped LAT single crystals were carried out. The doped LAT crystal is found to have efficiency higher than that of pure LAT crystal.

scholarly journals Purification and X-ray crystallographic analysis of 7-keto-8-aminopelargonic acid (KAPA) synthase fromMycobacterium smegmatis

2014 ◽  
Vol 70 (10) ◽  
pp. 1372-1375 ◽  
Author(s):  
Shanghua Fan ◽  
Defeng Li ◽  
Joy Fleming ◽  
Yuan Hong ◽  
Tao Chen ◽  
...  
Keyword(s):  
Crystallographic Analysis ◽  
Unit Cell ◽  
Monoclinic Space Group ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Essential Enzyme ◽  
Mycobacterial Growth

7-Keto-8-aminopelargonic acid synthase (KAPA synthase; BioF) is an essential enzyme for mycobacterial growth that catalyses the first committed step in the biotin-synthesis pathway. It is a pyridoxal 5′-phosphate (PLP)-dependent enzyme and is a potential drug target. Here, the cloning, expression, purification and crystallization of KAPA synthase fromMycobacterium smegmatis(MsBioF) and the characterization of MsBioF crystals using X-ray diffraction are described. The crystals diffracted to 2.3 Å resolution and belonged to the monoclinic space groupP21, with unit-cell parametersa= 70.88,b= 91.68,c= 109.84 Å, β = 97.8°. According to the molecular weight of MsBioF, the unit-cell parameters and the self-rotation function map, four molecules are present in each asymmetric unit with aVMvalue of 2.06 Å3 Da−1and a solvent content of 40.20%.

Synthesis and Characterization of Modified Diatomite-Leaf-Like CuO Nanosheet Composites

2018 ◽  
Vol 915 ◽  
pp. 93-97
Author(s):  
Filiz Boran
Keyword(s):  
Chemical Precipitation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure Morphology ◽  
Cuo Nanosheets ◽  
20 Nm ◽  
Modified Diatomite

In this work, firstly we described the effect of freeze drying on modification of raw diatomite. And then, modified diatomite-leaf-like copper oxide (CuO) nanosheet composite was successfully prepared by surfactant-free in-situ chemical precipitation method. The structure, morphology and elemental analysis of CuO nanosheets and its composite were analyzed by field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), fourier transform infrared (FTIR) spectroscopy and energy dispersive X-ray spectroscopy (EDAX). Dimensions of leaf-like CuO nanosheets were approximately determined as 160 nm in width, 320 nm in length and 20 nm in thickness. According to the EDAX spectrum, leaf-like CuO nanosheets composed of Cu and O atoms without any impurity and also uniformly covered the entire surface of modified diatomite.

Preparation and characterization of a novel solid solution of aluminum in tungsten carbide by mechanically activated high-temperature reaction

2006 ◽  
Vol 21 (7) ◽  
pp. 1700-1703 ◽  
Author(s):  
Junmin Yan ◽  
Xianfeng Ma ◽  
Wei Zhao ◽  
Huaguo Tang ◽  
Changjun Zhu ◽  
...  
Keyword(s):  
Solid Solution ◽  
High Temperature ◽  
Substitutional Solid Solution ◽  
Phase Identification ◽  
Temperature Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
High Temperature Reaction

In this work, a novel substitutional solid solution (W0.8Al0.2)C was synthesized by mechanically activated high-temperature reaction. X-ray diffraction was used for phase identification during the whole reaction process. Environment scanning electronic microscopy–field emission gun and energy dispersive x-ray were used to investigate the microstructure and the quantitative material composition of the specimen. (W0.8Al0.2)C was found to crystallize in the WC-type, and the cell parameters were a = 2.907(1) Å and c = 2.837(1) Å. The hardness of (W0.8Al0.2)C was tested to be 19.3 ± 1 GPa, and the density was 13.19 ± 0.05 g cm−3.

Synthesis and Characterization of TTAB Coated Silver (Ag) Nanoparticles

2011 ◽  
Vol 264-265 ◽  
pp. 530-534
Author(s):  
M.M. Alam ◽  
M. Harun ◽  
Momtazul Islam
Keyword(s):  
Silver Nanoparticles ◽  
Ag Nanoparticles ◽  
Silver Clusters ◽  
Ammonium Bromide ◽  
X Ray Diffraction ◽  
Preferential Growth ◽  
X Ray ◽  
Average Size ◽  
20 Nm

Silver nanoparticles protected by Tetradecyltrimethyl Ammonium Bromide (TTAB) were prepared in a one-phase electrochemical system. Electrochemical procedure, based on the dissolution of a metallic anode in an appropriate solvent, has been used to get silver nanoparticles. It is possible to get different particle size by changing the current density. The optical properties of the silver Nanoparticles were investigated by UV-Vis and Photoluminescence (PL) Spectroscopy. Absorption peak were found 424 nm which confirm the presence of Ag nanoparticles. The structural properties of the samples were carried out by scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. XRD confirmed the preferential growth of Ag nanoparticles whose average size is ≈ 20 nm in the <111> orientation as well as purity of silver clusters.

scholarly journals Microwave-Assisted Synthesis and Characterization of γ-MnO2 for High-Performance Supercapacitors

2021 ◽  
Author(s):  
Lorena Cuéllar-Herrera ◽  
Elsa Arce-Estrada ◽  
Antonio Romero-Serrano ◽  
José Ortiz-Landeros ◽  
Román Cabrera-Sierra ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
High Performance ◽  
Pore Diameter ◽  
Electrochemical Impedance ◽  
High Specific Capacitance ◽  
Microwave Assisted Synthesis ◽  
X Ray Diffraction ◽  
X Ray ◽  
20 Nm

AbstractTwo hydrothermal techniques under microwave irradiation were used to synthesize γ-MnO2 from 90°C to 150°C in 10−30 min. The first technique is based on reducing KMnO4 with MnSO4, and the second one involves liquid-phase oxidation between MnSO4 and (NH4)2S2O8. The structures and morphologies of the samples were analyzed using X-ray diffraction, scanning electron microscopy, and N2 physisorption measurements. The electrochemical properties were evaluated through cyclic voltammetry and electrochemical impedance spectroscopy. The γ-MnO2 materials obtained by the first technique mainly exhibited nanorods with diameters of 40–60 nm, and the samples obtained by the second technique showed flower-like microspheres with diameters of 1−2 µm; each flower was composed of nanosheets with a thickness of 10−20 nm. The processing time directly depends on the size of the nanorods. The sample synthesized by the first technique at 150°C and 10 min has the highest specific surface area of up to 59.08 m2 g−1 and mean pore diameter of 34.11 nm. Furthermore, this sample exhibits a near-rectangular cyclic voltammetry curves and high specific capacitance of 331.3 F g−1 in 0.1 M Na2SO4 solution at 5 mV s−1 scan rate. Graphic abstract

scholarly journals SYNTHESIS AND STRUCTURAL CHARACTERIZATION OF THE 1:1 PROTON TRANSFER SALT OF MALONIC ACID WITH P-CHLOROANILINE

2017 ◽  
Vol 14 (28) ◽  
pp. 66-71
Author(s):  
Gerson E. DELGADO ◽  
Lusbely BELANDRIA ◽  
Asiloé J. MORA ◽  
Julia BRUNO-COLMENÁREZ ◽  
Gustavo MARROQUÍN
Keyword(s):  
Hydrogen Bonds ◽  
Malonic Acid ◽  
Crystal Packing ◽  
Chemical Properties ◽  
Supramolecular Assembly ◽  
X Ray Diffraction ◽  
Monoclinic System ◽  
X Ray ◽  
Cell Parameters

The design of multicomponent crystals offers a means to modify the physicochemical properties of crystals without altering the chemical properties of a particular molecule. In this study, a multicomponent crystal, the salt of malonic acid with p-chloroaniline, was synthetized and structurally characterized. The title compound wasprepared by grinding in an agate mortar, and its structure was studied by powder and single-crystal X-ray diffraction. This compound crystallize in the monoclinic system with space group P21/c, Z = 4, and unit cell parameters a = 12.9776(7)Å, b = 9.2308(5)Å, c = 8.5170(5)Å, β = 93.474(3)°. The multicomponent compound, p-chloroanilinium semi-malonate, can be described as an ionic ensemble assisted by hydrogen bonds established between p-chloroanilinium cations and semi-malonate anions. The molecular structure and crystal packing are stabilized mainly by intermolecular O-H•••O and N-H•••O hydrogen bonds interactions. The molecules construct a supramolecular assembly with a two-dimensional hydrogen bonded network along the ca plane.

scholarly journals Phase equilibria in the SnBi2Te4MnBi2Te4 system and characterization of the Sn1-xMnxBi2Te4 solid solutions

2020 ◽  
Vol 21 (1) ◽  
pp. 113-116 ◽  
Author(s):  
E. Orujlu
Keyword(s):  
Phase Equilibria ◽  
Solid Solutions ◽  
Continuous Series ◽  
X Ray Diffraction ◽  
Incongruent Melting ◽  
Solidus Curve ◽  
Entire Concentration Range ◽  
X Ray ◽  
Cell Parameters

The phase diagram of the SnBi2Te4-MnBi2Te4 system was established over the entire concentration range by means of differential thermal analysis and powder X-ray diffraction techniques. It was shown that the system is non-quasi-binary due to the incongruent melting character of SnBi2Te4 and MnBi2Te4 compounds, but it is stable below solidus. The formation of a continuous series of solid solutions with the tetradymite-like layered structure was observed. Due to ionic radius differences of Mn2+ and Sn2+, both unit cell parameters of solid solutions increase linearly with the increasing amount of Sn. Phase equilibria above the solidus curve cannot be completed until the SnTe-MnTe-Bi2Te3 system fully studied.

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