Thermochemische Untersuchungen zu den Systemen SE2O3-SeO2. V. Ytterbiumselenoxide auf dem Schnitt Yb2O3-SeO2/Thermochemical Investigations of Systems RE2O3-SeO2. V. Ytterbium Selenium Oxides on the Line Yb2O3-SeO2

2002 ◽  
Vol 57 (8) ◽  
pp. 868-876 ◽  
Author(s):  
H. Oppermann ◽  
M. Zhang-Preße ◽  
P. Schmidt

The pure ternary phases on the line Yb2O3-SeO2 in thermodynamical equilibrium have been synthesized by solid state reaction and characterized using X-ray powder diffraction and IR-spectroscopy. There exist three phases: Yb2SeO5, Yb2Se3O9 and Yb2Se4O11, the last one with a homogeneiety range extending a higher SeO2-content. The thermal decompositions have been determined by total pressure measurements, and the thermodynamical data of the compounds have been derived. The phase diagram and the phase barogram have been established using the results of thermal analysis and total pressure measurements.

2001 ◽  
Vol 56 (9) ◽  
pp. 917-926 ◽  
Author(s):  
H. Oppermann ◽  
M. Zhang-Preβe

Abstract The pure ternary phases on the line Sm2O3-SeO2: Sm2SexO3+2x in thermodynamical equilibri­um have been synthesizied by solid state reactions and characterized by X-ray powder diffrac­tion, IR spectroscopy and DSC measurements. The existence of two new phases Sm2Se1,5O6 and Sm2Se4O11 was demonstrated besides the known phases Sm2Se3,5O10, Sm2Se3O9 and Sm2SeO5. The thermal decomposition properties of all compounds have been determined by total pressure measurements and the thermodynamical data of the compounds have been derived from their decomposition function and Cp-values. The phase diagram and the phase barogram have been estabilished using the results of DSC and total pressure measurements.


2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.


2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.


1995 ◽  
Vol 10 (4) ◽  
pp. 296-299 ◽  
Author(s):  
S. T. Misture ◽  
C. Park ◽  
R. L. Snyder ◽  
B. Jobst ◽  
B. Seebacher

Several compositions of the solid solutions (CaxSr1−x)CuO2 and (CaxSr1−x)2CuO3, both of which are found as minor phases in the high-temperature superconductors, were prepared by solid-state reaction. X-ray powder-diffraction patterns for three compositions of (CaxSr1−x)CuO2 and two for (CaxSr1−x)2CuO3 are presented.


1987 ◽  
Vol 2 (3) ◽  
pp. 176-179 ◽  
Author(s):  
G. Wilson ◽  
F. P. Glasser

AbstractA systematic survey of phase formation in the Na2O-ZrO2-SiO2 system has revealed inconsistencies in the number and identity of ternary phases, and of their X-ray powder data. The phases Na2ZrSiO5, Na4Zr2Si3O12, Na2ZrSi2O7 and Na2ZrSi4O11 were prepared by solid-state reaction and their experimental X-ray diffraction patterns measured. Calculated X-ray diffraction patterns were generated by computer, using published crystallographic data, and critically compared with the experimentally observed values. The unit-cell constants were redefined to a greater accuracy than the presently accepted values published in the Powder Diffraction File. Only Na4Zr2Si3O12 produced an X-ray diffraction pattern which agreed with that previously published; those from the other phases were significantly different in both the intensities and positions of the reflections. Data for synthetic Na2ZrSi4O11 identical to the mineral vlasovite are reported.


2002 ◽  
Vol 17 (1) ◽  
pp. 32-36 ◽  
Author(s):  
S. N. Tripathi ◽  
S. N. Achary ◽  
P. N. Namboodiri

The compound Th13Te24O74 was prepared by three independent methods, namely, thermal decomposition of ThTe2O6 in oxygen and argon and direct solid-state reaction of ThO2 and TeO2. The X-ray powder diffraction patterns of the three products, by and large, are similar, except for some differences in intensities and extra diffraction lines. The thermal decomposition of ThTe2O6 was carried out in the streams of oxygen and argon by thermogravimetry at a heating rate of 5 K/min in the temperature range of 725–840 °C. The solid-state reaction of ThO2 and TeO2 (13:24) was carried out in a sealed ampoule at 700 °C. The measured density of this compound is 8.23 g/cm3. An orthorhombic lattice with unit cell parameters, a=11.310±0.005 Å, b=14.064±0.006 Å, c=9.056±0.004 Å, and volume of 1440.419±1.088 (Å)3 was determined for this compound.


1992 ◽  
Vol 7 (1) ◽  
pp. 47-48 ◽  
Author(s):  
I. Krstanović ◽  
A. Radaković ◽  
Lj. Karanović

AbstractAn indexed X-ray powder diffraction pattern is reported for Ca4A6O12SO4, prepared by solid state reaction. The compound crystallizes in the tetragonal system with a = 13.031(3) and c = 9.164(2) Å, V = 1556.1 (8) Å3, Z = 4.


2009 ◽  
Vol 65 (6) ◽  
pp. i44-i44 ◽  
Author(s):  
Zhen-Hua Liang ◽  
Kai-Bin Tang ◽  
Qian-Wang Chen ◽  
Hua-Gui Zheng

Rubidium dicalcium triniobate(V), RbCa2Nb3O10, has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion–Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO3perovskite structure along theabplane. The rubidium ions (4/mmmsymmetry) are located in the interstitial space.


2014 ◽  
Vol 70 (12) ◽  
pp. 1138-1142 ◽  
Author(s):  
Le Li ◽  
Jian-Qing Tao

A twofold interpenetrating three-dimensional CdIIcoordination framework, [Cd(C8H3NO6)(C14H14N4)]n, has been prepared and characterized by IR spectroscopy, elemental analysis, thermal analysis and single-crystal X-ray diffraction. The asymmetric unit consists of a divalent CdIIatom, one 1,3-bis(2-methyl-1H-imidazol-1-yl)benzene (1,3-BMIB) ligand and one fully deprotonated 5-nitrobenzene-1,3-dicarboxylate (NO2-BDC2−) ligand. The coordination sphere of the CdIIatom consists of five O-donor atoms from three different NO2-BDC2−ligands and two imidazole N-donor atoms from two different 1,3-BMIB ligands, forming a distorted {CdN2O5} pentagonal bipyramid. The NO2-BDC ligand links three CdIIatomsviaa μ1-η1:η1chelating mode and a μ2-η2:η1bridging mode. The title compound is a twofold interpenetrating 3,5-connected network with the {42.65.83}{42.6} topology. In addition, the compound exhibits fluorescence emissions in the solid state at room temperature.


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