Laser Ablation Synthesis of Ceramic Powders

1990 ◽  
Vol 201 ◽  
Author(s):  
W. G. Fahrenholtz ◽  
S. R. Foltyn ◽  
K. C. Ott ◽  
M. Chadwick ◽  
D. M. Smith
Keyword(s):  
Thermal Analysis ◽  
Laser Ablation ◽  
Aluminum Oxide ◽  
Fine Powder ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Analysis Techniques ◽  
Aluminum Metal ◽  
Thermal Analysis Techniques

AbstractA pulsed excimer laser was used to ablate aluminum metal into an oxygen-containing atmosphere. The resulting fine powder was collected on a 0.1 μm filter and analyzed to determine structure and composition. Using a combination of TEM, EELS, and thermal analysis techniques, the product was found to be amorphous aluminum oxide, Al2O3. The morphology of the powders was investigated using SEM, TEM, and surface area measurements. The resulting powder was crystallized and examined by x-ray diffraction.

Kinetic Study on the Formation of the Aragonite-Like Phase Ba(CuOx)1-Y(CO3)y

1995 ◽  
Vol 398 ◽  
Author(s):  
A. Tomasi ◽  
E. Galvanetto ◽  
F.C. Matacotta ◽  
P. Nozar ◽  
P. Scardi ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
High Resolution Electron Microscopy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Formation Kinetics ◽  
Resolution Electron ◽  
Thermal Analysis Techniques ◽  
Kinetics Of

ABSTRACTA systematic study on phase formation and stabilisation in the Ba-Cu-C-O system in the temperature range 20-500°C, under various atmospheres, by traditional thermal analysis techniques, high temperature X-ray diffraction and high resolution electron microscopy, has permitted to identify and characterise the formation kinetics of a new copper containing phase isomorphic to γ-BaCO3.

Quasicrystalline Phase Formation in High Frequency Induction Melted Al80Cu14Fe6 Alloy

2013 ◽  
Vol 344 ◽  
pp. 37-41 ◽  
Author(s):  
H. Boularas ◽  
M.Y. Debili
Keyword(s):  
Thermal Analysis ◽  
High Frequency ◽  
Structural Characteristics ◽  
Quasicrystalline Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Thermal Analysis Techniques ◽  
Short Time ◽  
High Frequency Induction

Structural characteristics and thermal behavior of the conventionally solidified Al80Cu14Fe6, was investigated by X-ray diffraction, optical microscopy, and differential thermal analysis techniques. It was found that the formation of quasi crystalline phase occurs after annealing for relatively low temperature (500°C) during a short time.

scholarly journals Struvite Grown in Gel, Its Crystal Structure at 90 K and Thermoanalytical Study

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 89 ◽  
Author(s):  
Jolanta Prywer ◽  
Lesław Sieroń ◽  
Agnieszka Czylkowska
Keyword(s):  
Thermal Analysis ◽  
Sodium Metasilicate ◽  
X Ray Diffraction ◽  
Gel Growth ◽  
Growth Technique ◽  
Thermoanalytical Study ◽  
X Ray ◽  
Cell Parameters ◽  
Thermal Analysis Techniques ◽  
Derivative Thermogravimetry

In this article, we report the crystallization of struvite in sodium metasilicate gel by single diffusion gel growth technique. The obtained crystals have a very rich morphology displaying 18 faces. In this study, the habit and morphology of the obtained struvite crystals are analyzed. The crystals were examined and identified as pure struvite by single X-ray diffraction (XRD). The orthorhombic polar noncentrosymmetric space group Pmn21 was identified. The structure of the crystal was determined at a temperature of 90 K. Our research indicates a lack of polymorphism, resulting from the temperature lowering to 90 K, which has not been previously reported. The determined unit cell parameters are as follows a = 6.9650(2) Å, b = 6.1165(2) Å, c = 11.2056(3) Å. The structure of struvite is presented here with a residual factor R1 = 1.2% at 0.80 Å resolution. We also present thermoanalytical study of struvite using thermal analysis techniques such as thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA).

scholarly journals Structural Formation of UHMWPE Film Tracked by Real-Time Retardation Measurements during Uniaxial/Biaxial Stretching

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2292 ◽  
Author(s):  
Yoshinori Hashimoto ◽  
Shotaro Nishitsuji ◽  
Takashi Kurose ◽  
Hiroshi Ito
Keyword(s):  
Tensile Testing ◽  
X Ray Diffraction ◽  
Structural Formation ◽  
X Ray ◽  
Amorphous Phases ◽  
Analysis Techniques ◽  
Biaxial Stretching ◽  
Thermal Analysis Techniques ◽  
Ultra High Molecular Weight ◽  
Order Structures

This work reports on an experimental study of the stretching of ultra-high molecular weight polyethylene (UHMWPE) film in various uniaxial/biaxial stretching modes at various temperatures and stretching speeds. We examined the stress-birefringence relationship as a stress-optical rule (SOR) under uniaxial stretching and evaluated the stress-optical coefficient (SOC). Wide-angle X-ray diffraction (WAXD) measurements were applied to evaluate the contribution to birefringence of the crystalline and amorphous phases and to characterize stretching modes. In simultaneous biaxial stretching, the melting temperature (Tm) proved critical to structural formation. We applied thermal analysis techniques and tensile testing to evaluate higher order structures after each stretching mode.

Rotational Polymorphism of Methyl-Substituted Ammonium Perchlorates

1965 ◽  
Vol 9 ◽  
pp. 170-189 ◽  
Author(s):  
M. Stammler ◽  
R. Bruenner ◽  
W. Schmidt ◽  
D. Orcutt
Keyword(s):  
Phase Transition ◽  
Ammonium Perchlorate ◽  
Room Temperature ◽  
Decomposition Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Techniques ◽  
Cell Dimensions ◽  
Thermal Analysis Techniques ◽  
Space Requirements

AbstractThe thermal transformations which take place in solid methyl-substituted ammonium perchlorates have been studied using high-temperature X-ray diffraction and differential thermal analysis techniques. In the temperature range from 20°C to their decomposition temperature (above 300°C), ammonium perchlorate and tetramethyl ammonium perchlorate undergo only one enantiomorphic phase transition, namely at 240 and 340°C (with decomposition), respectively. This I—II transition is ascribed to the beginning of the free rotation of the ClO4− ions. The rotation of the cations, however, begins below room temperature. If the symmetry of the cation is lowered by having both methyl groups and hydrogens arranged around the nitrogen (as in monomethyl, dimethyl, and trimethyl ammonium perchlorates), there is an additional enantiomorphic phase transition. This I—II transformation is ascribed to the rotation of the cations which have, in the partially substituted ions, two sets of non-equivalent symmetry axes (different moments of inertia). The temperatures of transformation are discussed in terms of the space requirements for rotation. Symmetries and cell dimensions of some modifications were determined.

scholarly journals Synthesis, Microstructure and the Crystalline Structure of the Barium Titanate Ceramics Doped with Lanthanum

2013 ◽  
Vol 58 (4) ◽  
pp. 1305-1308 ◽  
Author(s):  
B. Wodecka-Duś ◽  
M. Plońska ◽  
D. Czekaj
Keyword(s):  
Thermal Analysis ◽  
Crystalline Structure ◽  
Diffraction Method ◽  
Simultaneous Thermal Analysis ◽  
Tetragonal Symmetry ◽  
X Ray Diffraction ◽  
Ceramic Powders ◽  
X Ray ◽  
Composition Formula ◽  
Titanate Ceramics

Abstract In the present study BaTiO3 and Ba1-xLaxTiO3 (0.1-0.4mol.% La) ceramic powders were synthesized by the conventional mixed oxide method (MOM). The characterization of the ceramic powders was carried out using a simultaneous thermal analysis (STA), with a combined DTA/TG/DTG system (Netzsch STA409). The results of thermal analysis allowed to determine the optimal temperature of synthesis. Microstructure was investigated by scanning electron microscopy (SEM), crystalline structure was studied by X-ray diffraction method (XRD). The EDS investigations showed that samples exhibited conservation of stoichiometry according to the chemical composition formula. The X-ray diffraction analysis confirmed formation of the desired crystalline structure both pure and La3+-doped BaTiO3 ceramics exhibiting a perovskite-type structure ABO3 with tetragonal symmetry P4 mm.

Structural and Thermal Characterization of Cyclodextrin - Suprofen Complexes

2007 ◽  
Vol 60 (2) ◽  
pp. 133 ◽  
Author(s):  
Pamela M. Dean
Keyword(s):  
Thermal Analysis ◽  
Single Crystal ◽  
Thermal Characterization ◽  
Uv Spectrophotometry ◽  
Stoichiometric Ratio ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Thermal Analysis Techniques

Suprofen, α-methyl-4-(2-thienylcarbonyl)benzeneacetic acid, a non-steroidal anti-inflammatory drug (NSAID), forms an inclusion complex with β-cyclodextrin of formula (β-cyclodextrin)2·(suprofen)·20H2O 1 and with TRIMEB (a permethylated β-cyclodextrin) of formula (β-cyclodextrin)·(suprofen)·0H2O 2. These species were investigated by thermal analysis techniques (HSM, TGA, DSC), powder X-ray diffraction (PXRD), and single-crystal X-ray diffraction at 173 K. Thermal analysis of 1 revealed dehydration followed by decomposition at 311.0°C, and only melting at 161.0°C for 2. The host-to-drug stoichiometric ratio was determined by UV spectrophotometry, and found to be 2:1 for 1 and 1:1 for 2. Single-crystal X-ray methods revealed that 1 crystallizes in the orthorhombic space group C2221, with a 19.0409(1), b 24.1949(2), c 32.4707(2) Å, and Z 4 formula units. Complex 2 crystallizes in the orthorhombic space group P212121, with a 15.389(1), b 21.051(1), c 27.027(2) Å, and Z 4 formula units. The (S)-enantiomer of suprofen was preferentially included in both characterized crystals.

scholarly journals CARACTERISATIONS PHYSICO-CHIMIQUES ET MINERALOGIQUES DE LARGILE DAKLAKOU UTILISEE DANS LA POTERIE EN VUE DE SON APPLICATION DANS LA FORMULATION DES AGREGATS LEGERS

2021 ◽  
Vol 9 (09) ◽  
pp. 706-712
Author(s):  
Moursalou Koriko ◽  
◽  
Dodji Zounon ◽  
Agbegnigan Degbe ◽  
Sanonka Tchegueni ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Quantitative Analysis ◽  
Chemical Analysis ◽  
Point Of View ◽  
Qualitative And Quantitative Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Qualitative And Quantitative ◽  
Analysis Techniques ◽  
Local Materials

In order to contribute to the enhancement of local materials, Aklakou clays taken from the quarry and used for pottery have been characterized from a physicochemical and mineralogical point of view. Thus, the samples taken from the quarry were subjected to chemical and mineralogical analyzes. Several qualitative and quantitative analysis techniques were used (chemical analysis, thermal analysis, X-ray diffraction and analysis by I.R. spectroscopy). These results demonstrated the richness of this quartz clay, resulting in a high proportion of silica (77.62%). This study was therefore essential before any application of this type of clay in the formulation of aggregates and pottery products or even ceramics in the broad sense. We can therefore conclude that the clays mined at the Aklakou quarry are very favorable materials for formulations of pottery products and in other fields such as the formulation of light aggregates.

scholarly journals Study on the fluorination of dysprosium oxide by ammonium bifluoride for the preparation of dysprosium fluoride

2021 ◽  
Vol 63 (8) ◽  
pp. 9-13
Author(s):  
Trong Hung Nguyen ◽  
◽  
Ba Thuan Le ◽  
Thanh Thuy Nguyen ◽  
◽  
...  
Keyword(s):  
Reaction Time ◽  
Composition Analysis ◽  
Fluoride Salt ◽  
X Ray Diffraction ◽  
Metallothermic Reduction ◽  
Dysprosium Oxide ◽  
X Ray ◽  
Analysis Techniques ◽  
Ammonium Bifluoride ◽  
Thermal Analysis Techniques

In this report, dysprosium fluoride (DyF3) - a material for the preparation of dysprosium (Dy) metal was prepared by the fluorination of dysprosium oxide (Dy2O3) by ammonium bifluoride (NH4HF2) reagent. The effect of reaction time and temperature on the formation of dysprosium fluoride salt has been studied. The phase composition and crystal structure of the obtained products were analysed by X-ray diffraction (XRD). Thermal analysis techniques were applied to determine the temperature range of the fluorination. Scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) was used for external morphology observation and chemical elemental composition analysis. The results showed that the high purity phase of DyF3 was formed at the conditions: reaction time and temperature of >1 h and >350oC, respectively. The product is available for the preparation of Dy metal by metallothermic reduction.

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