scholarly journals Synthesis, structural characterization and differential thermal analysis of the quaternary compound Ag2MnSnS4

2018 ◽  
Vol 64 (3) ◽  
pp. 216 ◽  
Author(s):  
Gerzon E. Delgado ◽  
N. Sierralta ◽  
M. Quintero ◽  
E. Quintero ◽  
E. Moreno ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Quaternary Compound ◽  
Cell Parameters ◽  
Temperature Modification ◽  
Chalcogenide Compound ◽  
High Temperature Modification

The quaternary chalcogenide compound Ag2MnSnS4 belonging to the system I2-II-IV-VI4 and synthesized by the melt and anneal technique, was characterized by Rietveld refinement of the powder X-ray diffraction data and differential thermal analysis (DTA). It was found that nS4 crystallizes in the orthorhombic space group Pmn21, with unit cell parameters a = 8:1705(5) Å, b = 6:9413(5) Å, c = 6:6532(5) Å, and V = 377:33(5) Å3, in a wurtzite-stannite structure. The DTA indicates that this compound melts at 790°C and that the phase relations which occurs in the material would be: α ➝ α + α1 ➝ α1 ➝ α1 + β ➝ β ➝ 1 + L ➝ L, were α is the orthorhombic wurtzite-stannite Pmn21 structure; α1 is a high temperature modification; and β and β1 are the zinc-blende structure and its high-temperature modification, respectively. 

scholarly journals Preparation, differential thermal analysis and crystal structure of the new quaternary compound CuVInSe3

2018 ◽  
Vol 64 (6) ◽  
pp. 548
Author(s):  
Gustavo Marroquin ◽  
Gerzon E. Delgado ◽  
Pedro Grima-Gallardo ◽  
Miguel Quintero
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Powder Diffraction ◽  
Powder Diffraction Data ◽  
Unit Cell Parameters ◽  
Quaternary Compound ◽  
X Ray ◽  
Cell Parameters ◽  
Structural Variables

The crystal structure of the quaternary compound CuVInSe3 belonging to the system (CuInSe2)1-x(VSe)x with x= ½, was analyzed using X-ray powder diffraction data. This material was synthesized by the melt and anneal method and crystallizes in the tetragonal space group P2c (Nº 112), with unit cell parameters a = 5.7909(4) Å, c = 11.625(1) Å, V = 389.84(5) Å3. The Rietveld refinement of 25 instrumental and structural variables led to Rexp = 6.6 %, Rp = 8.7 %, Rwp = 8.8 % and S = 1.3 for 4501 step intensities and 153 independent reflections. This compound has a normal adamantane structure and is isostructural with CuFeInSe3. The DTA indicates that this compound melts at 1332 K.

The new P-chalcopyrite compound Cu2FeIn2Se5; synthesis, thermal analysis (DTA), and crystal structure analysis by X-ray powder diffraction (XRPD)

2021 ◽  
Vol 67 (1 Jan-Feb) ◽  
pp. 18
Author(s):  
G. E. Delgado ◽  
P. Grima-Gallardo ◽  
J. A. Aitken ◽  
A. Cárdenas ◽  
I. Brito
Keyword(s):  
Crystal Structure ◽  
Thermal Analysis ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Chalcopyrite Structure ◽  
Distribution Analysis ◽  
X Ray Diffraction ◽  
Quaternary Compound ◽  
X Ray ◽  
Cell Parameters

The Cu2FeIn2Se5 alloy, belonging to the system (CuInSe2)1-x(FeSe)x with x= ⅓, was synthesized by the melt and annealing technique. The differential thermal analysis (DTA) indicates that this compound melts at 1017 K. The crystal structure of this new quaternary compound was established using powder X-ray diffraction. Cation distribution analysis indicates that this material crystallizes in a P-chalcopyrite structure, space group P2c (Nº 112), with unit cell parameters a = 6.1852(2) Å, c = 12.3633(9) Å, V = 472.98(4) Å3. Cu2FeIn2Se5 is a new adamantane type compound derivative of the sphalerite structure, and consists of a three-dimensional arrangement of distorted CuSe4, FeSe4, and InSe4 tetrahedral connected by common faces.

Zur Kenntnis des Argyrodit-Strukturtyps: Die Kristallstruktur von Ag8SiS6 / The Argyrodite Structure Type : The Crystal Structure of Ag8SiS6

1977 ◽  
Vol 32 (4) ◽  
pp. 373-379 ◽  
Author(s):  
Bernt Krebs ◽  
Jürgen Mandt
Keyword(s):  
Crystal Structure ◽  
High Temperature ◽  
Room Temperature ◽  
Structure Type ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Temperature Modification ◽  
Face Centered ◽  
Temperature Factors ◽  
High Temperature Modification

The room temperature modification of Ag8SiS6 is orthorhombic, space group Pna21, with α = 15.024, b = 7.428, c = 10.533 Å, Z = 4. A complete single crystal X-ray structure analysis shows the structure to contain tetrahedral SiS4(4-) units (Si-S 2.094(12) ... 2.130(12) Å) besides isolated sulfide groups coordinated by Ag; the compound may thus be formulated as Ag8(SiS4)(S)2. The coordination of the Ag atoms by sulfur is distorted tetrahedral (Ag-S 2.557...2.757 A), approximately trigonal planar (Ag-S 2.386...2.775 A, with one additional weakly bonded axial S at 2.991 ... 3.330 Å), or linear (Ag-S 2.414... 2.443 Å). Within the (ordered) Ag sublattice the temperature factors are significantly higher than for Si and S, indicating a certain mobility of the Ag atoms. The arrangement of the thiosilicate -sulfide part of the structure is pseudocubic face-centered, showing the close structural relationship to the disordered cubic high temperature modification of Ag8GeTe6.

Alkali sulfates with aphthitalite-like structures from fumaroles of the Tolbachik Volcano, Kamchatka, Russia. I. MetathÉnardite, a natural high-temperature modification of Na2SO4

2019 ◽  
Vol 57 (6) ◽  
pp. 885-901 ◽  
Author(s):  
Igor V. Pekov ◽  
Nadezhda V. Shchipalkina ◽  
Natalia V. Zubkova ◽  
Vladislav V. Gurzhiy ◽  
Atali A. Agakhanov ◽  
...  
Keyword(s):  
High Temperature ◽  
Scoria Cone ◽  
New Mineral ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cell Parameters ◽  
Three Samples ◽  
Tolbachik Volcano ◽  
Synthetic Phase ◽  
High Temperature Modification

Abstract A new mineral, metathénardite, ideally Na2SO4, the high-temperature hexagonal dimorph of thénardite, a natural analogue of the synthetic phase Na2SO4(I), was found in the sublimates of active fumaroles at the Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure eruption, Tolbachik volcano, Kamchatka, Russia. The holotype originates from the Glavnaya Tenoritovaya fumarole in which metathénardite is associated with hematite, tenorite, fluorophlogopite, sanidine, anhydrite, krasheninnikovite, vanthoffite, glauberite, johillerite, and lammerite. The cotypes 1 and 2 are from the Arsenarnaya (with hematite, tenorite, fluorophlogopite, sanidine, euchlorine, wulffite, anhydrite, fluoborite, johillerite, nickenichite, calciojohillerite, badalovite, tilasite, cassiterite, and pseudobrookite) and the Yadovitaya (with tenorite, euchlorine, fedotovite, dolerophanite, langbeinite, krasheninnikovite, anhydrite, and hematite) fumaroles, respectively. All specimens with metathénardite were collected from areas with temperatures of 350–400 °C. Metathénardite forms hexagonal tabular, lamellar, or dipyramidal crystals (forms: {001}, {100}, {102}, and {201}) up to 3 mm combined in crusts up to several hundred cm2 in area. The mineral is transparent to semitransparent, colorless, white, light-blue, greenish, yellowish, grayish or brownish, with vitreous luster. Dmeas. = 2.72(1), Dcalc. = 2.717 g/cm3. Metathénardite is optically uniaxial (–), ω = 1.489(2), ε = 1.486(2). The empirical formulae are (Na1.92K0.05Ca0.02Zn0.01)[S0.99O4] (holotype), (Na1.54K0.22Ca0.09Cu0.01Mg0.01)[S1.00O4] (cotype 1), and Na1.65K0.11Ca0.05Cu0.04Mg0.01)[S1.01O4] (cotype 2). Admixed K and bivalent cations probably stabilize the hexagonal aphthitalite-like structure of metathénardite at room temperature. The crystal structure was solved using single crystals of all three samples, R1 = 0.0852, 0.0452, and 0.0449 for holotype and cotypes 1 and 2, respectively. The space group is P63/mmc, and the unit-cell parameters of the holotype are a = 5.3467(9), c = 7.0876(16) Å, V = 157.47(6) Å3, and Z = 2. The strongest reflections of the powder X-ray diffraction pattern [d,Å(I)(hkl)] are: 4.667(27)(100), 3.904(89)(101), 3.565(33)(002), 2.824(94)(102), 2.686(100)(110), and 1.939(35)(202). Metathénardite and thénardite clearly differ from one another in X-ray diffraction data and infrared and Raman spectra.

scholarly journals Differential Thermal Analysis and High Temperature Powder X-ray Diffraction of 2 CaO⋅SiO2

1963 ◽  
Vol 71 (805) ◽  
pp. 105-108 ◽  
Author(s):  
Goro YAMAGUCHI ◽  
Yoshio ONO ◽  
Shigeo KAWAMURA ◽  
Yoshiaki SODA
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
X Ray Diffraction ◽  
X Ray

scholarly journals THE QUATERNARY CHALCOGENIDE COMPOUND Ag2FeGeSe4: A REVISION OF THEIR CRYSTAL STRUCTURE AND MAGNETIC PROPERTIES

2021 ◽  
Vol 18 (38) ◽  
pp. 85-99
Author(s):  
Gerzon E. DELGADO ◽  
Pilar DELGADO-NIÑO ◽  
Eugenio QUINTERO
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Solar Cell ◽  
Chemical Analysis ◽  
Rietveld Method ◽  
Orthorhombic Space Group ◽  
Quaternary Compound ◽  
Space Group ◽  
Cell Parameters ◽  
Chalcogenide Compound

Background: Quaternary compounds bellowing to the I2-II-IV-VI4 system are of considerable technological interest due to their possible use in the preparation of solar cell and thermoelectric materials devices. In recent years, considerable attention has been focused on the detailed study of quaternary chalcogenide compounds related to the chalcopyrite compounds, particularly AgInSe2, which has emerged as a leading material for the preparation of photovoltaic devices due to their potential applications in solar cell technology. Aims: This work focuses on synthesis, chemical analysis, thermal study, magnetism measurement, and crystal structural characterization of the quaternary semiconductor Ag2FeGeSe4, an essential member of the family I2-II-IV-VI4. Methods: This material was synthesized by the melt and anneal technique. The chemical analysis was carried out by scanning electron microscopy (SEM) and differential thermal analysis (DTA). Magnetic susceptibility () as a function of temperature and magnetization as a function of the magnetic field were also performed, and crystal structure analysis was made employing the Rietveld method with powder X-ray diffraction data. Results and Discussion: The preparation confirms the formation of the quaternary compound with stoichiometric 2:1:1:4 according to the chemical analysis. This quaternary compound melt at 1015 K, and show an antiferromagnetic behavior with Neel temperature TN of 240 K. The Debye temperature (D) estimated for this compound was 194 K. The quaternary chalcogenide compound Ag2FeGeSe4 crystallizes in the orthorhombic space group Pmn21, Z = 4, with unit cell parameters: a = 7.6478(1) Å, b = 6.5071(1) Å, c = 6.4260(1) Å, and V = 319.79(1) Å3, in a wurtzite-stannite arrangement with a Cu2CdGeS4-type structure, which is characterized by a three-dimensional arrangement of slightly distorted AgSe4, FeSe4, and GeSe4 tetrahedra connected by corners. In this structure, each Se atom is coordinated by four cations located at the corners of a slightly distorted tetrahedron, and each cation is tetrahedrally bonded to four anions. Conclusions: The melt and anneal method remains effective for preparing compounds chalcogenides as the quaternary Ag2FeGeSe4, a new member of I2-II-IV-VI4 family of semiconductors, which crystallizes in the non-centrosymmetric space group Pmn21 with diamond-like structure. The crystal structure information of this compound allows explaining their magnetic properties, which in combination with its semiconductor properties make this material a potential aspirant for different applications, mainly in solar cells.

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