scholarly journals Investigation of Bi2O3-rich part of Bi2O3-PbO phase diagram

2017 ◽  
Vol 82 (12) ◽  
pp. 1433-1444
Author(s):  
Aleksandra Dapcevic ◽  
Dejan Poleti ◽  
Ljiljana Karanovic ◽  
Jelena Miladinovic

A new Bi-rich part of Bi2O3?PbO phase diagram was determined using differential thermal analysis and X-ray powder diffraction techniques. Four solid solutions, ?-Bi2O3, ?-Bi2O3, ?-Bi2O3 and ?ss-Bi8Pb5O17, can be distinguished below 37.5 mol % of PbO and one compound, ?2-Bi8Pb5O17. Two of them, ?-Bi2O3 and ?ss-Bi8Pb5O17 are high-temperature phases. The large field of ?-Bi2O3 stability was implemented making the crucial difference comparing to phase diagrams from the Bi2O3?PbO system published so far.

1971 ◽  
Vol 49 (8) ◽  
pp. 1315-1316 ◽  
Author(s):  
A. N. Campbell ◽  
W. H. W. Wood

The Ag–Ca system has been reinvestigated over the composition range 50–100 atomic % Ca, by differential thermal analysis and high temperature X-ray powder diffraction. Our results are in good agreement with those of Alexander et al. (1) and those of Pascal et al. (2) in the region 50–59 atomic % Ca, but the peritectic claimed by Alexander et al., lying at 50% Ca and 598 °C, appears not to exist, according to our DTA and X-ray results. Here and elsewhere our results substantiate those of Pascal et al. We also find that the compound AgCa3 is formed peritectically, and not congruently as suggested by Alexander et al.


Author(s):  
Chengfu Xu ◽  
Zhengfei Gu ◽  
Yongquan Yang ◽  
Dongdong Ma ◽  
Gang Cheng ◽  
...  

Abstract The phase relations in the Ce2Co17-Sm2Co17 system over the whole concentration range have been studied by means of Xray powder diffraction, differential thermal analysis and scanning electron microscopy equipped with energy dispersive Xray spectroscopy. The X-ray powder diffraction results reveal that all the alloys (Ce1-xSmx)2Co17 are similar to the end member of the investigated system, Sm2Co17. It is implied that continuous solid solutions are formed in this system. The lattice parameters and unit cell volumes of (Ce1-xSmx)2Co17 solid solutions increase linearly with x increasing from 0 to 1.0. The occurrence of the polymorphic transformation reaction α-(Ce, Sm)2Co17 = β-(Ce, Sm)2Co17 is confirmed in the Ce2Co17-Sm2Co17 system, but its transition temperature cannot be determined. The differential thermal analysis measurements show that both the decomposition temperature and the Curie temperature of the (Ce1-xSmx)2Co17 alloys increase gradually with increasing Sm content. Based on the X-ray powder diffraction results and differential thermal analysis data, the tentative vertical section of Ce2Co17-Sm2Co17 pseudobinary system has been constructed.


1967 ◽  
Vol 45 (2) ◽  
pp. 131-137 ◽  
Author(s):  
T. E. Rummery ◽  
R. D. Heyding

The rhodium/selenium system has been examined by room temperature X-ray powder diffraction patterns and by differential thermal analysis. A tentative phase diagram has been obtained. Eleven phases were observed, five of which were previously known. The compounds β-RhSe1.29, α-RhSe1.32, and α-RhSe1.34 have lattices based on the B81 structure; RhSe2+x and RhSe2.67 have defect pyrite lattices. The compound α-RhSe1.95 is isomorphous with IrSe2. The structures of RhSe1±0.1, β-RhSe1.34, α- and β-RhSe1.50, and RhSe1.9 are not yet known.


2021 ◽  
Vol 0 (4) ◽  
pp. 67-70
Author(s):  
Z.T. Hasanova ◽  

Differential thermal analysis and powder X-ray diffraction methods were used for phase equilibria studying in the Cu3AsSe4-GeSe2 system. It was established that wide (up to 30 mol.%) solid solutions based on Cu3AsSe4 are formed. GeSe2-rich alloys consist of various heterogeneous mixtures, including phases outside the T–x plane of this section


2018 ◽  
Vol 64 (6) ◽  
pp. 548
Author(s):  
Gustavo Marroquin ◽  
Gerzon E. Delgado ◽  
Pedro Grima-Gallardo ◽  
Miguel Quintero

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.


1964 ◽  
Vol 8 ◽  
pp. 78-85 ◽  
Author(s):  
P. K. Gantzel ◽  
S. Langer ◽  
N. L. Baldwin ◽  
F. L. Kester

AbstractThermal analyses of samples of thorium dicarbide in equilibrium with graphite show arrests which indicate phase transitions at 1427 ± 21°C arid 1481 ± 28°C. These thermal effects have been observed on heating and cooling both in standard thermal analysis and in differential thermal analysis using graphite as a reference material. The microstructure of thorium dicarbide samples shows the characteristic “herringbone” pattern of a material which has undergone a martensitic-type transition.A high-temperature X-ray investigation has revealed that the observed thermal arrests correspond to erystallographic transformations. The monodinic modification found at room temperature is stable to 1427°C, at which temperature a tetragonal modification with a0 = 4.235 ± 0.002Å and c0 = 5.408 ± 0.002Å is formed. At 1481°C, the tetragonal is transformed to cubic with a0 = 5.809 ± 0.002 Å. The best agreement between observed and calculated intensities has been obtained with C-C units of 1.5-Å assumed bond length in space groups P42/mmc and Pa3 for the tetragonal and cubic modifications, respectively.


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.


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.


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