scholarly journals Crystal structure and electrical properties of Ag6PS5I single crystal

2021 ◽  
Vol 24 (1) ◽  
pp. 26-33
Author(s):  
I.P. Studenyak ◽  
◽  
A.I. Pogodin ◽  
M.J. Filep ◽  
O.P. Kokhan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Single Crystal ◽  
Rietveld Method ◽  
Chemical Deposition ◽  
Ion Diffusion ◽  
Crystallization Method ◽  
Vertical Zone ◽  
Impedance Spectroscopy Technique ◽  
Nyquist Plots

The single crystals of quaternary halogen Ag6PS5I were grown from the solution–melt by means of a vertical zone crystallization method. The crystal structure has been ascertained using the Rietveld method. Investigation of electrical conductivity was carried out using the impedance spectroscopy technique within the frequency range 1·101 – 3·105 Hz and temperature interval 293–383 K on gold contacts applied by chemical deposition from solution. Ionic (1.79·10-3 S/cm) and electronic (1.64·10-6 S/cm) components of electrical conductivity have been determined using the Nyquist plots. The mechanism of ionic conductivity for Ag6PS5I single crystal has been proposed which can be considered as ion diffusion through “channels” Ag2–Ag2.

scholarly journals Electrical properties of cation-substituted Ag7(Si1–xGex)S5I single crystals

2021 ◽  
Vol 24 (3) ◽  
pp. 241-247
Author(s):  
I.P. Studenyak ◽  
◽  
A.I. Pogodin ◽  
I.A. Shender ◽  
M.J. Filep ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electrical Properties ◽  
Single Crystals ◽  
Solid Solutions ◽  
Frequency Range ◽  
Electronic Components ◽  
High Quality ◽  
Crystallization Method ◽  
Vertical Zone ◽  
Nyquist Plots

High-quality single crystals of Ag7(Si1–xGex)S5I (x = 0.2, 0.4, 0.6, 0.8) solid solutions are grown from the solution–melt by vertical zone crystallization method. The measurements of electrical conductivity of Ag7(Si1–xGex)S5I solid solutions were performed using the impedance spectroscopy method within the frequency range from 10 Hz up to 2·106 Hz and temperature interval 293–383 K. Ionic and electronic components of electrical conductivity, as well as their ratios, were determined using the Nyquist plots.

Single-crystal structure and electrical conductivity of 1,2,3-trimethylimidazolium bis(4,5-dimercapto-1,3-dithiole-2-thionato)nickelate(III)

1990 ◽  
Vol 29 (20) ◽  
pp. 3933-3935 ◽  
Author(s):  
Derk Reefman ◽  
Joost P. Cornelissen ◽  
Jaap G. Haasnoot ◽  
Rudolf A. G. De Graaff ◽  
Jan Reedijk
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Single Crystal ◽  
Single Crystal Structure

Redefinition of satimolite

2018 ◽  
Vol 82 (5) ◽  
pp. 1033-1047 ◽  
Author(s):  
Igor V. Pekov ◽  
Natalia V. Zubkova ◽  
Dmitry A. Ksenofontov ◽  
Nikita V. Chukanov ◽  
Vasiliy O. Yapaskurt ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Three Dimensional ◽  
Direct Methods ◽  
Salt Dome ◽  
Unit Cell ◽  
Unit Cell Parameters ◽  
Cell Parameters ◽  
Octahedral Clusters

ABSTRACTThe borate mineral satimolite, which was first described in 1969 and remained poorly-studied until now, has been re-investigated (electron microprobe analysis, single-crystal and powder X-ray diffraction studies, crystal-structure determination, infrared spectroscopy) and redefined based on the novel data obtained for the holotype material from the Satimola salt dome and a recently found sample from the Chelkar salt dome, both in North Caspian Region, Western Kazakhstan. The revised idealized formula of satimolite is KNa2(Al5Mg2)[B12O18(OH)12](OH)6Cl4·4H2O (Z = 3). The mineral is trigonal, space group R$\bar{3}$m, unit-cell parameters are: a = 15.1431(8), c = 14.4558(14) Å and V = 2870.8(4) Å3 (Satimola) and a = 15.1406(4), c = 14.3794(9) Å and V = 2854.7(2) Å3 (Chelkar). The crystal system and unit-cell parameters are quite different from those reported previously. The crystal structure of the sample from Chelkar was solved based on single-crystal data (direct methods, R = 0.0814) and the structure of the holotype from Satimola was refined on a powder sample by the Rietveld method (Rp = 0.0563, Rwp = 0.0761 and Rall = 0.0667). The structure of satimolite is unique for minerals. It contains 12-membered borate rings [B12O18(OH)12] in which BO3 triangles alternate with BO2(OH)2 tetrahedra sharing common vertices, and octahedral clusters [M7O6(OH)18] with M = Al5Mg2 in the ideal case, with sharing of corners between rings and clusters to form a three-dimensional heteropolyhedral framework. Each borate ring is connected with six octahedral clusters: three under the ring and three over the ring. Large ellipsoidal cages in the framework host Na and K cations, Cl anions and H2O molecules.

X-ray Diffraction Study of the Crystal Structure of the Tl Ternary Chalcogenides Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9

1998 ◽  
Vol 54 (4) ◽  
pp. 358-364 ◽  
Author(s):  
K. G. Hatzisymeon ◽  
S. C. Kokkou ◽  
A. N. Anagnostopoulos ◽  
P. I. Rentzeperis
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Rietveld Method ◽  
Direct Methods ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Volume Decrease

A series of thallium ternary chalcogenides with the composition Tl2x In2(1−x)Se2, x = 0.2, 0.3,...0.9, have been studied by X-ray powder and, for some of them, single-crystal diffraction. They are tetragonal, space group I4/mcm, Z = 4, and isostructural with the binary semiconductor TlSe. Their crystal structures have been solved by direct methods and refined by the Rietveld method to a precision which is satisfactorily comparable to single-crystal results. As x is changed from x = 0.2 to x = 0.9 the unit-cell parameters and volume decrease or increase following Kurnakov's law, which is valid for solid solutions. Refined positional parameters of Se, In—Se and Tl—Se bond lengths vary with x also according to the same law. The distribution of In and Tl cations in 4(a) and 4(b) sites depends on the stoichiometry x and the crystals are composed of [In3+Se2]_{\infty}^- chains along the c axis in which InSe4 tetrahedra share edges; the chains are interconnected with Tl+(In+) ions.

Solving the Crystal Structure of Cd5(OH)8(NO3)2·2H2O from Powder Diffraction Data. A Comparison with Single Crystal Data

1991 ◽  
Vol 6 (1) ◽  
pp. 10-15 ◽  
Author(s):  
Patricia Bénard ◽  
Michèle Louër ◽  
Daniel Louër
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Rietveld Method ◽  
Subsequent Treatment ◽  
Crystal Data ◽  
Powder Diffraction Data ◽  
Indexing Method ◽  
Parameter Values

AbstractA comparison between the results of ab initio structure determination from X-ray powder diffraction data of a new cadmium hydroxide nitrate, Cd5(OH)8 (NO3)2·2H2O (SG C2/m), and those obtained from single crystal data is presented. The powder diffraction pattern has been analysed by an indexing method and fitting techniques. A total of 119 unambiguously indexed reflections has been extracted and used in subsequent treatment. The power of powder techniques to index the pattern and to find the structure model by normal Patterson and Fourier methods is clearly shown. The refinement of approximate coordinates has been carried out by the Rietveld method (444 reflections). The comparison of results with those obtained from single crystal data (2218 reflections) shows that the precision of positional parameter values is lower by a factor of 10, on average, in the powder study. These results are discussed in terms of crystallographic parameters (number of reflections used, number of parameters to refine, contrast between atoms) and, also, in terms of sample dependent properties (preferred orientation effect, impurity). Finally, the crystal structure has been derived from powder data with a precision probably sufficient for most purposes.

Structure Re-determination of LASSBio-294 – a cardioactive compound of the N-acylhydrazone class – using X-ray powder diffraction data

2013 ◽  
Vol 28 (S2) ◽  
pp. S491-S509 ◽  
Author(s):  
Fanny N. Costa ◽  
Fabio Furlan Ferreira ◽  
Tiago F. da Silva ◽  
Eliezer J. Barreiro ◽  
Lídia M. Lima ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Goodness Of Fit ◽  
Rietveld Method ◽  
Therapeutic Interventions ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Cell Parameters

Many N-acylhydrazone derivatives synthetized in LASSBio® cannot be prepared as single crystals of sufficient size and/or quality for structure determination to be carried out using single crystal X-ray diffraction techniques. This article highlights the opportunity for determining crystal structures of this class of compounds directly from powder diffraction data. For this task, the crystal structure of LASSBio-294 was re-determined by means of conventional X-ray powder diffraction data and so, compared with the crystal structure already determined for single crystal data. LASSBio-294 is a cardioactive compound of the N-acylhydrazone class, which can become part of the therapeutic interventions designed to decrease exertional fatigue, and, consequently, improve the quality of life of patients suffering from chronic heart failure. Its final crystal structure was refined by means of the Rietveld method (Rietveld, 1967; 1969). This drug crystallizes in a monoclinic (P21/c) space group, with unit cell parameters a = 11.3413(3) Å, b = 12.3573(4) Å, c = 9.0158(3) Å, β = 89.821(2)°, V = 1263.55(7) Å3, Z = 4, Ź = 1 and ρcalc = 1.4419(1) g cm−3. The goodness-of-fit indicator and R-factors were, respectively: χ2 = 1.203, RBragg = 0.696%, Rwp = 5.59%, Rexp = 4.65% and Rp = 4.18%. The molecules in LASSBio-294 are H-bonded along the c-axis involving the atoms N(3)–H(8)···O(4).

scholarly journals PRODUCTION OF HYIGH-PURITY ZINC SINGLE CRYSTALS BY VERTICAL DIRECTED CRYSTALLIZATION METHOD

2020 ◽  
pp. 17-20
Author(s):  
A.P. Shcherban ◽  
G.P. Kovtun ◽  
D.A. Solopikhin ◽  
Yu.V. Gorbenko ◽  
T.Yu. Rudycheva ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Single Crystals ◽  
High Purity ◽  
Growth Direction ◽  
Directed Crystallization ◽  
Micro Structure ◽  
Crystalline Perfection ◽  
Impurity Composition ◽  
Crystallization Method

A seedless process has been developed to produce high-purity Zn single crystals by the method of vertical di-rected crystallization from a melt. The output of a single crystal structure is from 60 to 80%. Crystals with different growth directions were obtained: [1015] and [0002]. The deviation angles of the growth direction plane relative to the normal to the axis of the sample are 0.5...6°. Microhardness, crystalline perfection of single crystals and micro-structure have been determined. The impurity composition of the start and end parts of single crystals produced from initial grades of zinc of various purities was studied. The developed process can be used to grow single crystals low-melting metals, such as Cd, Pb, Te, In, Bi, Sn, etc.

Structure determination of diclofenac in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data

2004 ◽  
Vol 37 (2) ◽  
pp. 288-294 ◽  
Author(s):  
Nongnuj Muangsin ◽  
Malee Prajuabsook ◽  
Pitiporn Chimsook ◽  
Nuanphun Chantarasiri ◽  
Krisana Siraleartmukul ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structure Determination ◽  
Rietveld Method ◽  
Powder Diffraction Data ◽  
X Ray ◽  
Chitosan Matrix

The structure determination of diclofenac embedded in a diclofenac-containing chitosan matrix using conventional X-ray powder diffraction data is demonstrated. It reveals that sodium diclofenac, the starting material in the preparation of a controlled-release diclofenac-containing chitosan matrix, changes to diclofenac acid in space groupC2/cin the matrix. Simple methods were employed for handling the sample to obtain X-ray powder diffraction data of sufficiently high quality for the determination of the crystal structure of diclofenac embedded in chitosan. These involved grinding and sieving several times through a micro-mesh sieve to obtain a suitable particle size and a uniformly spherical particle shape. A traditional technique for structure solution from X-ray powder diffraction data was applied. The X-ray diffraction intensities were extracted using Le Bail's method. The structure was solved by direct methods from the extracted powder data and refined using the Rietveld method. For comparison, the single-crystal structure of the same drug was also determined. The result shows that the crystal structure solved from conventional X-ray powder diffraction data is in good agreement with that of the single crystal. The deviations of the differences in bond lengths and angles are of the order of 0.030 Å and 0.639°, respectively.

Visualizing lithium ions in the crystal structure of Li3PO4 by in situ neutron diffraction

2021 ◽  
Vol 54 (5) ◽  
Author(s):  
Maykel Manawan ◽  
Evvy Kartini ◽  
Maxim Avdeev
Keyword(s):  
Crystal Structure ◽  
Neutron Diffraction ◽  
Density Distribution ◽  
Rietveld Method ◽  
Lithium Ion ◽  
Bond Valence ◽  
Nuclear Density ◽  
Ion Diffusion ◽  
In Situ Neutron Diffraction

Li3PO4 is known to demonstrate Li+ ionic conductivity, making it a good candidate for solid electrolytes in all-solid batteries. Understanding the crystal structure and its connection to Li+ diffusion is essential for further rational doping to improve the ionic transport mechanism. The purpose of this study is to investigate this mechanism using anisotropic displacement parameters (ADPs), nuclear density distribution and bond valence mapping. In situ neutron powder diffraction experiments have been performed using the high-resolution powder diffractometer ECHIDNA at the OPAL reactor, Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, NSW, Australia. The ADPs and nuclear density distribution were determined from the analysis of neutron diffraction data using the Rietveld method, whereas the bond valence map was calculated from the refined structure. The crystal structure remained unchanged as the temperature was increased (3, 100, 300 and 400 K). However, the ADPs show a greater increase in anisotropy in the a and b axes compared with the c axis, indicating the tendency of the ionic movement. By combining nuclear density distribution and bond valence mapping, the most likely lithium-ion diffusion in the crystal structure can be visualized.

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