scholarly journals Synthesis and X-ray-graphical characteristics of the MеSn2F5 (Mе = Na, K, Rb, Cs) fluoride-ion conductors

Author(s):  
R. M. Zakalyukin ◽  
E. A. Levkevich ◽  
A. V. Nikolaeva

Objectives. Pentafluorodistannates of alkali metals are promising materials for use as electrolytes in fluoride-ion batteries due to their electrophysical properties, such as high fluoride-ion conductivity. This work aims to synthesize crystals of alkali metals MeSn2F5 (Me = Na, K, Rb, Cs), carry out X-ray diffraction studies on them, and investigate the possibility of obtaining lithium fluorostannates.Methods. Supersaturated aqueous solutions were employed to synthesize the crystals. The X-ray diffraction (XRD) analysis was carried out.Results. Oversaturated solutions yield microcrystalline powders of sodium, potassium, rubidium, and cesium pentafluorodistannates. The presence of a single-phase was confirmed by XRD analysis of the powders corresponding to the MеSn2F5 (Mе = Na, K, Rb, Cs) composition. XRD data analysis and literature indicated that MеSn2F5 (Mе = K, Rb, Cs) have a fluorite-like structure, with the cations forming three-layer closest packing. The RbSn2F5 compound was discovered to be isostructural to KSn2F5. Based on this discovery, RbSn2F5 was reindexed to a hexagonal unit cell with parameters a = 7.40(3) Å, с = 10.12(6) Å (KSn2F5 P3, a = 7.29(3) Å, с = 9.86(2) Å). The CsSn2F5 compound was reindexed to a monoclinic unit cell (a = 10.03(4) Å, b = 5.92(7) Å, c = 11.96(9) Å, β = 107.4(5)°). A crystallochemical analysis of the pentafluorodistannates was carried out, and common structural motifs were discovered. The motifs are similar to lead tetrafluorostannate PbSnF4, the best fluoride-ion conductor. The effect of the pentafluorodistannates structures on the ionic conductivity is considered. The LiF–SnF2 system contains no compounds; the compositions were obtained by melting the original fluorides. Conclusions. MеSn2F5 (Mе = Na, K, Rb, Cs) were synthesized and investigated by XRD analysis. The structural characteristics of the RbSn2F5 and CsSn2F5 compounds have been redefined. The crystallochemical structure is analyzed in relation to the electrophysical properties of the alkali metal pentafluorodistannates. Pentafluorodistannates MеSn2F5 (Mе = K, Rb, Cs) have a fluorite-like structural motif with cubic parameters а = 5.694 Å (KSn2F5), а = 5.846 Å (RbSn2F5), а = 6.100 Å (CsSn2F5), with the cations forming three-layer closest packing. The cationic layers alternate like Me–Sn–Sn–Me (Mе = K, Rb, Cs). For KSn2F5 and RbSn2F5, they are normal to the three-fold axis and normal to the four-fold axis in the case of CsSn2F5.

2008 ◽  
Vol 23 (2) ◽  
pp. 121-124 ◽  
Author(s):  
Mark A. Rodriguez ◽  
Timothy J. Boyle ◽  
Pin Yang ◽  
Damon L. Harris

A specially designed specimen holder employing a beryllium dome has been fabricated for collection of X-ray diffraction (XRD) data from highly reactive materials. The specimen holder has a robust O-ring type seal (<10−9Torr) and no observed intensity artifacts in the 1° to 150° 2θ range. The design also minimizes specimen displacement errors and allows for analysis of both powders and bulk specimens (i.e., pellets). The simple design makes for straightforward assembly of the holder within the confines of a glove box. XRD analysis of hygroscopic LaBr3 powders collected with this holder are suitable for Rietveld structure refinement, yielding unit cell lattice parameters of a=7.9703(6) Å and c=4.5122(6) Å; cell volume=248.44(6) Å3; Rp=7.70%.


TAPPI Journal ◽  
2011 ◽  
Vol 10 (1) ◽  
pp. 17-23
Author(s):  
KEVIN TAYLOR ◽  
RICH ADDERLY ◽  
GAVIN BAXTER

Over time, performance of tubular backpulse pressure filters in kraft mills deteriorates, even with regular acid washing. Unscheduled filter replacement due to filter plugging results in significant costs and may result in mill downtime. We identified acid-insoluble filter-plugging materials by scanning electron microscope/energy-dispersion X-ray spectroscopy (SEM/EDS) and X-ray diffraction (XRD) analysis in both polypropylene and Gore-Tex™ membrane filter socks. The major filter-plugging components were calcium sulfate (gypsum), calcium phosphate (hydroxylapatite), aluminosilicate clays, metal sulfides, and carbon. We carried out detailed sample analysis of both the standard acid-washing procedure and a modified procedure. Filter plugging by gypsum and metal sulfides appeared to occur because of the acid-washing procedure. Gypsum formation on the filter resulted from significant hydrolysis of sulfamic acid solution at temperatures greater than 130°F. Modification of the acid-washing procedure greatly reduced the amount of gypsum and addition of a surfactant to the acid reduced wash time and mobilized some of the carbon from the filter. With surfactant, acid washing was 95% complete after 40 min.


Author(s):  
A. Kareem Dahash Ali ◽  
Nihad Ali Shafeek

This study included the fabrication of    compound (Tl2-xHgxBa2-ySryCa2Cu3O10+δ) in a manner solid state and under hydrostatic pressure ( 8 ton/cm2) and temperature annealing(850°C), and determine the effect of the laser on the structural and electrical properties elements in the compound, and various concentrations of x where (x= 0.1,0.2,0.3 ). Observed by testing the XRD The best ratio of compensation for x is 0.2 as the value of a = b = 5.3899 (A °), c = 36.21 (A °) show that the installation of four-wheel-based type and that the best temperature shift is TC= 142 K  .When you shine a CO2 laser on the models in order to recognize the effect of the laser on these models showed the study of X-ray diffraction of these samples when preparing models with different concentrations of the values ​​of x, the best ratio of compensation is 0.2 which showed an increase in the values ​​of the dimensions of the unit cell a=b = 5.3929 (A °), c = 36.238 (A°). And the best transition temperature after shedding laser is TC=144 K. 


Author(s):  
Erdoğan Karip ◽  
Mehtap Muratoğlu

People are exposed to different kinds of diseases or various accidents in life. Hydroxyapatite (HA) has been widely employed for bone treatment applications. In this study, HA was extracted from sheep bones. Bio-composites were doped with 1, 5, and 10 wt.% of expanded perlite and 5 wt.% of ZrO2–MgO-P2O5. The bio-composites were prepared by the cold isostatic pressing method (250 MPa) and sintered at 900°C for 1 h. In order to evaluate the characteristics of the bio-composites, microhardness, density, X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) analyses were carried out on them. Additionally, the specimens whose characteristics were determined were kept in synthetic body fluid (SBF), and their in vitro behavior was examined. As a result, it was observed that microhardness increased as both the weight and the grain size of the expanded perlite were increased. Calcium silicate, tri-calcium phosphate, and hydroxyapatite were observed in the XRD analysis of all samples, and the formation of apatite structures was increased by addition of ZrO2–MgO–P2O5.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2949
Author(s):  
Marzieh Rabiei ◽  
Arvydas Palevicius ◽  
Amir Dashti ◽  
Sohrab Nasiri ◽  
Ahmad Monshi ◽  
...  

Taking into account X-ray diffraction, one of the well-known methods for calculating the stress-strain of crystals is Williamson-Hall (W–H). The W-H method has three models, namely (1) Uniform deformation model (UDM); (2) Uniform stress deformation model (USDM); and (3) Uniform deformation energy density model (UDEDM). The USDM and UDEDM models are directly related to the modulus of elasticity (E). Young’s modulus is a key parameter in engineering design and materials development. Young’s modulus is considered in USDM and UDEDM models, but in all previous studies, researchers used the average values of Young’s modulus or they calculated Young’s modulus only for a sharp peak of an XRD pattern or they extracted Young’s modulus from the literature. Therefore, these values are not representative of all peaks derived from X-ray diffraction; as a result, these values are not estimated with high accuracy. Nevertheless, in the current study, the W-H method is used considering the all diffracted planes of the unit cell and super cells (2 × 2 × 2) of Hydroxyapatite (HA), and a new method with the high accuracy of the W-H method in the USDM model is presented to calculate stress (σ) and strain (ε). The accounting for the planar density of atoms is the novelty of this work. Furthermore, the ultrasonic pulse-echo test is performed for the validation of the novelty assumptions.


2021 ◽  
Vol 7 (3) ◽  
pp. 42
Author(s):  
Jiba N. Dahal ◽  
Kalangala Sikkanther Syed Ali ◽  
Sanjay R. Mishra

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th2Fe17 structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy2Fe17. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe3 and NbFe2 secondary phases at x = 1.0. The hyperfine field of Dy2Fe16Ga1−xNbx decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.


Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1969
Author(s):  
Riccardo Scarfiello ◽  
Elisabetta Mazzotta ◽  
Davide Altamura ◽  
Concetta Nobile ◽  
Rosanna Mastria ◽  
...  

The surface and structural characterization techniques of three atom-thick bi-dimensional 2D-WS2 colloidal nanocrystals cross the limit of bulk investigation, offering the possibility of simultaneous phase identification, structural-to-morphological evaluation, and surface chemical description. In the present study, we report a rational understanding based on X-ray photoelectron spectroscopy (XPS) and structural inspection of two kinds of dimensionally controllable 2D-WS2 colloidal nanoflakes (NFLs) generated with a surfactant assisted non-hydrolytic route. The qualitative and quantitative determination of 1T’ and 2H phases based on W 4f XPS signal components, together with the presence of two kinds of sulfur ions, S22− and S2−, based on S 2p signal and related to the formation of WS2 and WOxSy in a mixed oxygen-sulfur environment, are carefully reported and discussed for both nanocrystals breeds. The XPS results are used as an input for detailed X-ray Diffraction (XRD) analysis allowing for a clear discrimination of NFLs crystal habit, and an estimation of the exact number of atomic monolayers composing the 2D-WS2 nanocrystalline samples.


Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 852
Author(s):  
Asiful H. Seikh ◽  
Hossam Halfa ◽  
Mahmoud S. Soliman

Molybdenum (Mo) is an important alloying element in maraging steels. In this study, we altered the Mo concentration during the production of four cobalt-free maraging steels using an electroslag refining process. The microstructure of the four forged maraging steels was evaluated to examine phase contents by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. Additionally, we assessed the corrosion resistance of the newly developed alloys in 3.5% NaCl solution and 1 M H2SO4 solution through potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Furthermore, we performed SEM and energy-dispersive spectroscopy (EDS) analysis after corrosion to assess changes in microstructure and Raman spectroscopy to identify the presence of phases on the electrode surface. The microstructural analysis shows that the formation of retained austenite increases with increasing Mo concentrations. It is found from corrosion study that increasing Mo concentration up to 4.6% increased the corrosion resistance of the steel. However, further increase in Mo concentration reduces the corrosion resistance.


2020 ◽  
Vol 849 ◽  
pp. 113-118
Author(s):  
Yayat Iman Supriyatna ◽  
Slamet Sumardi ◽  
Widi Astuti ◽  
Athessia N. Nainggolan ◽  
Ajeng W. Ismail ◽  
...  

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.


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