Determination of ultrasound velocity and attenuation in single crystals by means of x‐ray diffraction

1993 ◽  
Vol 64 (5) ◽  
pp. 1274-1279 ◽  
Author(s):  
E. Zolotoyabko ◽  
V. Panov ◽  
D. Schvarkov
Keyword(s):  
Single Crystals ◽  
Ultrasound Velocity ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals Rubidium tetrafluoridobromate(III): redetermination of the crystal structure from single-crystal X-ray diffraction data

IUCrData ◽  
2019 ◽  
Vol 4 (11) ◽  
Author(s):  
Artem V. Malin ◽  
Sergei I. Ivlev ◽  
Roman V. Ostvald ◽  
Florian Kraus
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
Diffraction Data ◽  
Structure Type ◽  
X Ray Diffraction ◽  
X Ray ◽  
Square Planar ◽  
Atomic Coordinates

Single crystals of rubidium tetrafluoridobromate(III), RbBrF4, were grown by melting and recrystallizing RbBrF4 from its melt. This is the first determination of the crystal structure of RbBrF4 using single-crystal X-ray diffraction data. We confirmed that the structure contains square-planar [BrF4]− anions and rubidium cations that are coordinated by F atoms in a square-antiprismatic manner. The compound crystallizes in the KBrF4 structure type. Atomic coordinates and bond lengths and angles were determined with higher precision than in a previous report based on powder X-ray diffraction data [Ivlev et al. (2015). Z. Anorg. Allg. Chem. 641, 2593–2598].

scholarly journals Determination of the Chemical Composition of Lithium Niobate Powders

Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 340 ◽  
Author(s):  
Oswaldo Sánchez-Dena ◽  
Carlos J. Villagómez ◽  
César D. Fierro-Ruíz ◽  
Artemio S. Padilla-Robles ◽  
Rurik Farías ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Lithium Niobate ◽  
Single Crystals ◽  
Structure Refinement ◽  
Linear Equations ◽  
Powdered Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scattering Effects

Existent methods for determining the composition of lithium niobate single crystals are mainly based on their variations due to changes in their electronic structure, which accounts for the fact that most of these methods rely on experimental techniques using light as the probe. Nevertheless, these methods used for single crystals fail in accurately predicting the chemical composition of lithium niobate powders due to strong scattering effects and randomness. In this work, an innovative method for determining the chemical composition of lithium niobate powders, based mainly on the probing of secondary thermodynamic phases by X-ray diffraction analysis and structure refinement, is employed. Its validation is supported by the characterization of several samples synthesized by the standard and inexpensive method of mechanosynthesis. Furthermore, new linear equations are proposed to accurately describe and determine the chemical composition of this type of powdered material. The composition can now be determined by using any of four standard characterization techniques: X-Ray Diffraction (XRD), Raman Spectroscopy (RS), UV-vis Diffuse Reflectance (DR), and Differential Thermal Analysis (DTA). In the case of the existence of a previous equivalent description for single crystals, a brief analysis of the literature is made.

Electric properties of KTiOPO4and NaTiOPO4from temperature-dependent X-ray diffraction

1999 ◽  
Vol 32 (1) ◽  
pp. 1-10 ◽  
Author(s):  
S. Dahaoui ◽  
N. K. Hansen ◽  
J. Protas ◽  
H.-G. Krane ◽  
K. Fischer ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Single Crystals ◽  
Electrostatic Potential ◽  
Pyroelectric Coefficient ◽  
Atomic Scale ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
A Value

Single crystals of KTiOPO4(KTP) and NaTiOPO4(NaTP) show pronounced pyroelectric behaviour. In order to determine the origin of this property on an atomic scale, X-ray diffraction measurements have been carried out at several temperatures between 100 and 600 K. Modelling of the electron density and the evolution of the structure as a function of temperature has enabled the determination of values for the spontaneous polarization of the compounds and the pyroelectric coefficient of KTP, principally due to the alkaline-ion displacements with a value of 2.0 nC cm−2 K−1. Structure modifications, compared with NaTiOPO4, and the calculation of the electrostatic potential explain the anisotropic behaviour of ionic conductivity of KTP single crystals.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

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