Conductivity Characterizationof Iron Oxide Doped 8 mol% Yttria Stabilized Zirconia

2018 ◽  
Vol 280 ◽  
pp. 58-64
Author(s):  
Tinesha Selvaraj ◽  
Johar Banjuraizah ◽  
S.F. Khor ◽  
M.N. Mohd Zainol
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Solid Electrolytes ◽  
Electrode Materials ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
Solid Electrode ◽  
Short Sample ◽  
X Ray ◽  
Rietveld Quantitative Phase Analysis

A facile strategy was proposed to incorporate the dopant Fe into 8YSZ-based material, which can be potentially applied as solid electrode materials for Solid Oxide Fuel Cells (SOFC). In this study, 8YSZ powder was investigated in terms of densification, conductivity and thecrystal structure as a solid electrolytes. Therefore, varying mol% of Fe included 1, 2, and 3 were prepared for investigation. The crystalline structure of the pristine and Fe doped samples were characterized by X-ray diffraction (XRD) and the phase contents were evaluated by using the Rietveld method. Rietveld quantitative phase analysis demonstrates that the monoclinic-ZrO2phase increases (12.8 wt% to 39.7 wt%) as the concentration of Fe increases, while the amount of tetragonal-ZrO2phase drop (40.4 wt% to 11.9 wt%) dramatically. Sintering activity was applied to improve incorporation of the 8YSZ powder and the dopant Fe where the relative density increases from 77% to 92%. Sample YSZ-2Fe has been fitted with CPE equivalent circuit and achieved 6.251 x 10-6S/cm at 300 °C in air. However, it was found that conductivity levels decreased as the mol% of Fe increased. In short, sample YSZ-2Fe ceramic demonstrated good results in terms of densification (92.09%), cubic ZrO2phase (22 wt%) and conductivity 6.251 x 10-6S/cm.

scholarly journals Synthesis and characterization of Na-P1 (GIS) zeolite using a kaolinitic rock

2020 ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio
Keyword(s):  
Inductively Coupled Plasma ◽  
Rietveld Method ◽  
Ambient Pressure ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Inductively Coupled

Abstract This work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 ° and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods.The results make the experimental protocol very promising for an industrial transfer.

scholarly journals Structural, morphological and electrical properties of multi-doped calcium phosphate materials as solid electrolytes for intermediate temperature solid oxide fuel cells

2018 ◽  
Vol 50 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Miljana Mirkovic ◽  
Anja Dosen ◽  
Suzana Eric ◽  
Marija Stojmenovic ◽  
Branko Matovic ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Solid Electrolytes ◽  
Complex Impedance ◽  
Cost Effective ◽  
Precipitation Method ◽  
Partial Substitution ◽  
Acetate Solution ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effective Synthesis

Modified solution precipitation method was used to prepare pure and doped Mg, Sr and Na hydroxyapatite type materials (CaP, CaMgP and CaSrNaP). Modification consisted of partial substitution of nitrates by acetate solution in order to achieve a more soluble and cost effective synthesis. The obtained samples were calcined at 400?C (CaP400, CaMgP400 and CaSrNaP400). All powders were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). Calcined samples were densified at 1000?C in an air for 3 h (CaP1000, CaMgP1000 and CaSrNaP1000). Sintered samples were characterized by XRPD, FTIR, SEM, EDS and complex impedance methods. The highest conductivity was found for the multi-doped phosphate sample (CaSrNaP1000) at 700?C (1.90?10-3?-1cm-1). The corresponding activation energies of conductivity amounted to 0.31 eV in the temperature range 500-700?C.

scholarly journals Psilocybin: crystal structure solutions enable phase analysis of prior art and recently patented examples

2022 ◽  
Vol 78 (1) ◽  
Author(s):  
Alexander M. Sherwood ◽  
Robert B. Kargbo ◽  
Kristi W. Kaylo ◽  
Nicholas V. Cozzi ◽  
Poncho Meisenheimer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Rietveld Refinement ◽  
Phase Analysis ◽  
Density Functional ◽  
Rietveld Method ◽  
Quantitative Phase Analysis ◽  
Published Data ◽  
Dihydrogen Phosphate ◽  
X Ray Diffraction ◽  
X Ray

Psilocybin {systematic name: 3-[2-(dimethylamino)ethyl]-1H-indol-4-yl dihydrogen phosphate} is a zwitterionic tryptamine natural product found in numerous species of fungi known for their psychoactive properties. Following its structural elucidation and chemical synthesis in 1959, purified synthetic psilocybin has been evaluated in clinical trials and has shown promise in the treatment of various mental health disorders. In a recent process-scale crystallization investigation, three crystalline forms of psilocybin were repeatedly observed: Hydrate A, Polymorph A, and Polymorph B. The crystal structure for Hydrate A was solved previously by single-crystal X-ray diffraction. This article presents new crystal structure solutions for the two anhydrates, Polymorphs A and B, based on Rietveld refinement using laboratory and synchrotron X-ray diffraction data, and density functional theory (DFT) calculations. Utilizing the three solved structures, an investigation was conducted via Rietveld method (RM) based quantitative phase analysis (QPA) to estimate the contribution of the three different forms in powder X-ray diffraction (PXRD) patterns provided by different sources of bulk psilocybin produced between 1963 and 2021. Over the last 57 years, each of these samples quantitatively reflect one or more of the hydrate and anhydrate polymorphs. In addition to quantitatively evaluating the composition of each sample, this article evaluates correlations between the crystal forms present, corresponding process methods, sample age, and storage conditions. Furthermore, revision is recommended on characterizations in recently granted patents that include descriptions of crystalline psilocybin inappropriately reported as a single-phase `isostructural variant.' Rietveld refinement demonstrated that the claimed material was composed of approximately 81% Polymorph A and 19% Polymorph B, both of which have been identified in historical samples. In this article, we show conclusively that all published data can be explained in terms of three well-defined forms of psilocybin and that no additional forms are needed to explain the diffraction patterns.

The decomposition of konyaite: importance in CO2 fixation in mine tailings

2010 ◽  
Vol 74 (5) ◽  
pp. 903-917 ◽  
Author(s):  
S. J. Mills ◽  
S. A. Wilson ◽  
G. M. Dipple ◽  
M. Raudsepp
Keyword(s):  
Western Australia ◽  
Mine Tailings ◽  
Mine Drainage ◽  
Rietveld Method ◽  
Time Frame ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Mount Keith

AbstractThe sodium-magnesium hydrated double salt konyaite, Na2Mg(SO4)2·5H2O, has been studied by single-crystal X-ray diffraction and thermogravimetry on synthetic samples and by quantitative X-ray diffraction utilizing the Rietveld method on natural samples from the Mount Keith mine, Western Australia. Konyaite crystallizes in space group P21/c, with the cell parameters: a = 5.7594(10), b = 23.914(4), c = 8.0250(13) Å, β = 95.288(9)°, V = 1100.6(3) Å3 and Z = 4. The crystal structure has been refined to R1 = 3.41% for 2155 reflections [Fo>4σ(Fo)] and 6.44% for all 3061 reflections, with all atoms located.Quantitative phase analysis utilizing the Rietveld method was undertaken on five samples of konyaite-bearing mine tailings from the Mount Keith Nickel Mine, Western Australia. Konyaite was found to decompose over time and after 22 months had transformed to other sulphate and amorphous phases. Blödite did not increase in any ofthe samples indicating that konyaite may not always transform to blödite. Over the same time frame, synthetic konyaite completely decomposed to a mixture of thenardite (Na2SO4), hexahydrite (MgSO4·6H2O), blödite (Na2Mg(SO4)2·4H2O) and löweite (Na12Mg7(SO4)13). Detection of konyaite and other Mg-rich sulphates is important in terms of CO2 fixation. Magnesium bound to sulphate mineral phases reduces the overall potential of tailings piles to lock up atmospheric carbon in Mg carbonates, such as hydromagnesite. Amorphous sulphates are also highly reactive and may contribute to acid mine drainage ifpresent in large quantities, and may dissolve carbonate phases which have already sequestered carbon.

scholarly journals Influence of diopside: feldspar ratio in ceramic reactions assessed by quantitative phase analysis (X-ray diffraction - Rietveld method)

Cerâmica ◽  
2013 ◽  
Vol 59 (350) ◽  
pp. 345-350 ◽  
Author(s):  
L. Kuzmickas ◽  
F. R. D. Andrade ◽  
G. A. J. Szabó ◽  
J. F. M. Motta ◽  
M. Cabral Jr
Keyword(s):  
Mechanical Properties ◽  
Iron Content ◽  
Rietveld Method ◽  
Physical And Mechanical Properties ◽  
Relative Mass ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Potassic Feldspar ◽  
Proportional Reduction

White ceramics were produced with raw mixtures prepared with varying proportions of diopside-rich rock (0 to 20 wt.%) and potassic feldspar (40 to 20 wt.%), and fixed proportions of kaolinite (40 wt.%) and quartz (20 wt.%), fired in a temperature range from 1170 to 1210 ºC. The phases identified in the experimental ceramics were quartz, anorthite, mullite and glass, and their relative mass proportions were determined by X-ray diffraction (Rietveld method). The addition of diopside as a partial substitute for potassic feldspar causes the formation of a calcium silicate, analogous of the natural anorthite (CaSi2Al2O8) in the ceramics, with proportional reduction in its glass and mullite contents. Water absorption and porosity of the ceramic bodies clearly decrease with increasing firing temperature, while the effect of the raw mixture composition on the physical and mechanical properties of the ceramics is less evident. Diopside-rich rock has low iron content (1.5 wt.% Fe2O3) and, therefore, promotes white burning.

scholarly journals Synthesis and characterization of Na-P1 (GIS) zeolite using a kaolinitic rock

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniela Novembre ◽  
Domingo Gimeno ◽  
Alessandro Del Vecchio
Keyword(s):  
Inductively Coupled Plasma ◽  
Rietveld Method ◽  
Ambient Pressure ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Quantitative Phase Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Inductively Coupled

AbstractThis work focuses on the hydrothermal synthesis of Na-P1 zeolite by using a kaolinite rock coming from Romana (Sassari, Italy). The kaolin is calcined at a temperature of 650 °C and then mixed with calculated quantities of NaOH. The synthesis runs are carried out at ambient pressure and at variable temperatures of 65 and 100 °C. For the first time compared to the past, the Na-P1 zeolite is synthesized without the use of additives and through a protocol that reduces both temperatures and synthesis times. The synthesis products are analysed by X-ray diffraction, high temperature X-ray diffraction, infrared spectroscopy, scanning electron microscopy and inductively coupled plasma optical emission spectrometry. The cell parameters are calculated using the Rietveld method. Density and specific surface area are also calculated. The absence of amorphous phases and impurities in synthetic powders is verified through quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The results make the experimental protocol very promising for an industrial transfer.

Accuracy in Rietveld quantitative phase analysis of Portland cements

2003 ◽  
Vol 36 (5) ◽  
pp. 1169-1176 ◽  
Author(s):  
A. G. De la Torre ◽  
M. A. G. Aranda
Keyword(s):  
Rietveld Method ◽  
High Energy ◽  
Tricalcium Silicate ◽  
Dicalcium Silicate ◽  
Cement Industry ◽  
Quantitative Phase Analysis ◽  
Portland Cements ◽  
X Ray ◽  
Relative Errors ◽  
Rietveld Quantitative Phase Analysis

The polymorphs that constitute most Portland cements have been synthesized: tricalcium silicate, dicalcium silicate, aluminate, ferrite, gypsum, bassanite and calcite. They have been used to prepare artificial mixtures,i.e.white Portland clinker, grey Portland clinker and two types of grey Portland cements. Quantitative mineralogical analyses of these mixtures have been obtained by laboratory X-ray powder diffraction (λ = 1.54 Å) and the Rietveld method. To assess the accuracy of these analyses, high-energy synchrotron X-ray powder data (λ = 0.40 Å) for the same mixtures have also been studied. Furthermore, synchrotron X-ray powder data were collected for binary mixtures of the polymorphs and a corundum standard. This was done to determine the presence of impurity crystalline phases in the synthesized samples and to check the presence of non-negligible amorphous phase contents. The errors in the synchrotron X-ray analyses are quite low (usually smaller than 1 wt%). The relative errors in the laboratory X-ray analyses are of the order of 2% for the main phases and increase to approximately 5–10% for the low-content components. These errors are acceptable in the factory environment and the routine application of this methodology in the cement industry is being implemented.

In situ X-ray diffraction techniques as a powerful tool to study battery electrode materials

2002 ◽  
Vol 47 (19) ◽  
pp. 3137-3149 ◽  
Author(s):  
M. Morcrette ◽  
Y. Chabre ◽  
G. Vaughan ◽  
G. Amatucci ◽  
J.-B. Leriche ◽  
...  
Keyword(s):  
Electrode Materials ◽  
X Ray Diffraction ◽  
X Ray ◽  
Battery Electrode

X-ray powder diffraction data of LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites

2021 ◽  
pp. 1-6
Author(s):  
Mariana M. V. M. Souza ◽  
Alex Maza ◽  
Pablo V. Tuza
Keyword(s):  
Crystal Structure ◽  
Rietveld Method ◽  
Pechini Method ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Modified Pechini Method ◽  
Scanning Electron

In the present work, LaNi0.5Ti0.45Co0.05O3, LaNi0.45Co0.05Ti0.5O3, and LaNi0.5Ti0.5O3 perovskites were synthesized by the modified Pechini method. These materials were characterized using X-ray fluorescence, scanning electron microscopy, and powder X-ray diffraction coupled to the Rietveld method. The crystal structure of these materials is orthorhombic, with space group Pbnm (No 62). The unit-cell parameters are a = 5.535(5) Å, b = 5.527(3) Å, c = 7.819(7) Å, V = 239.2(3) Å3, for the LaNi0.5Ti0.45Co0.05O3, a = 5.538(6) Å, b = 5.528(4) Å, c = 7.825(10) Å, V = 239.5(4) Å3, for the LaNi0.45Co0.05Ti0.5O3, and a = 5.540(2) Å, b = 5.5334(15) Å, c = 7.834(3) Å, V = 240.2(1) Å3, for the LaNi0.5Ti0.5O3.

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