Equilibrium phases in the BeSO4-H2O system

1966 ◽  
Vol 19 (5) ◽  
pp. 751 ◽  
Author(s):  
IJ Bear ◽  
AG Turnbull

The equilibrium phases of the BeSO4-H2O system were studied by vapour hydration of BeSO4 and equilibration of thermally produced mixtures. Tetra-, di-, and mono-hydrate are the stable hydrates with no solid solution regions between them. X-ray and infrared spectra are presented for these hydrates and a provisional phase diagram drawn.��� Reversible transitions of BeS04 were found at 588° and 639°, the latter showing a hysteresis splitting of 4° on cooling. Transition heats of 1.2 ± 0.1 and 0.5 ± 0.1 kcal/mole respectively were found by differential thermal analysis.

2011 ◽  
Vol 284-286 ◽  
pp. 2090-2093 ◽  
Author(s):  
Xue Liang Xiong ◽  
Zhi Yang ◽  
Hong Yong Ouyang

The character of ilmenite was modified by pretreatment, the effect of pre-oxidation temperature and time on structure of ilmenite were investigated by X-ray diffraction(XRD) and Thermo-gravimetric/differential thermal analysis. The results indicated that new microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared on the surface of mineral below 800°C, but evident rutile crystals and pseudobrookite Fe2O3·TiO2 were appeared above 850°C with the structure of ilmenite disrupting simultaneously. The preoxidation time increased from 15min to 60min, evident microcrystal rutile and FeTiO3·Fe2O3 solid solution were appeared by degrees without structure of ilmenite breaking.


2013 ◽  
Vol 200 ◽  
pp. 50-53
Author(s):  
Inna A. Ivashchenko ◽  
Volodumur V. Halyan ◽  
Irina V. Danylyuk ◽  
Volodumur Z. Pankevuch ◽  
Georgij Y. Davydyuk ◽  
...  

The phase diagram of the Ga2Se3–In2Se3 system was investigated by differential-thermal analysis (DTA) and X-ray diffraction (XRD) method. The single crystals from the area of existence of the γ2 phase with the compositions (Ga0.6In0.4)2Se3 and (Ga0.594In0.396Er0.01)2Se3 were grown by a vertical Bridgman method. Absorption spectra of the grown crystals were studied. The estimated optical band gap is 1.95±0. 01 eV. The resistance of the single crystals of (Ga0.6In0.4)2Se3 (R=500 MΩ) and (Ga0.594In0.396Er0.01)2Se3 (R=210 MΩ) was measured.


2021 ◽  
pp. 43-47
Author(s):  
P.R. Mammadli ◽  

The character of the mutual interaction of the components in the CuI-SbI3 system was studied by differential thermal analysis and X-ray phase analysis methods and its phase diagram was constructed. It was found that the system is quasi-binary and forms a monotectic phase diagram. The immiscibility region covers ~15-93 mol% SbI3 concentration interval at the monotectic equilibrium temperature (~ 4930С). The temperatures of polymorphic transformations of the CuI compound in the system drop slightly and these phase transitions take place by metatectic reactions


2010 ◽  
Vol 43 (1) ◽  
pp. 33-37 ◽  
Author(s):  
Ch. F. Xu ◽  
Z. F. Gu ◽  
G. Cheng ◽  
H. Y. Zhou ◽  
Z. M. Wang ◽  
...  

The phase diagram of the Nd–Pt system from 35 to 85 at%Pt has been revised using X-ray diffraction and differential thermal analysis. It is found that the Nd3Pt4phase with the rhombohedral Pd4Pu3structure type is unstable and decomposes into the two neighboring phases NdPt and NdPt2at temperatures ranging approximately from 583 to 1123 K. It is confirmed that the homogeneity range for the Laves phase NdPt2extends from about 68.5 to 75.3 at%Pt in the Nd–Pt binary system. The polymorphic transformation temperature of α-NdPt ⇌ β-NdPt is about 623 K, where the α-NdPt phase with BFe type is stable at low temperatures and the β-NdPt phase with BCr type at high temperatures.


2000 ◽  
Vol 15 (9) ◽  
pp. 1905-1910 ◽  
Author(s):  
H. Takeda ◽  
M. Okuno ◽  
M. Ohgaki ◽  
K. Yamashita ◽  
T. Matsumoto

The phase diagram of the Sm2O3–CuO system was investigated by the combination of the differential thermal analysis and the quench method. The results showed that Sm2CuO4 incongruently melts at about 1220 °C, and that the solid Sm2CuO4 exists in equilibrium with the liquid consisting of 81–95 mol% CuO in the range of 1060–1220 °C. On the basis of the phase diagram, Sm2−xCexCuO4 single crystals were grown by the traveling solvent floating zone method. The crystal structure [space group I4/mmm, a = 3.917(1), c 4 11.899(2) Å] has been refined using single-crystal x-ray diffraction data with a precision corresponding to an R index of 0.02.


1999 ◽  
Vol 14 (7) ◽  
pp. 2929-2932 ◽  
Author(s):  
S. K. Chung ◽  
S. J. Shin ◽  
A. A. Andriiko ◽  
P. V. Rudenok

The products obtained from MnO2–V2O5 mixtures at the ambient oxygen pressure and temperatures up to 900 °C were studied by means of thermal analysis and x-ray diffraction methods. The following phases were found to exist in equilibrium, depending on the composition: (I) Mn2O3–Mn2V2O7, (II) Mn2V2O7–MnV2O6, and (III) V2O5–solid solution of VO2 in MnV2O6. A phase diagram was obtained for the composition region III. The data are instructive for syntheses of manganese vanadates by thermal methods.


2012 ◽  
Vol 476-478 ◽  
pp. 1318-1321
Author(s):  
Qi Zhi Cao ◽  
Jing Zhang

Nanostructured Fe25Al57.5Ni17.5intermetallics was prepared directly by mechanical alloying (MA) in a high-energy planetary ball-mill. The phase transformations and structural changes occurring in the studied material during mechanical alloying were investigated by X-ray diffraction (XRD). Thermal behavior of the milled powders was examined by differential thermal analysis (DTA). Disordered Al(Fe,Ni) solid solution was formed at the early stage. After 50 h of milling, Al(Fe,Ni) solid solution transformed into Al3Ni2,AlFe3,AlFe0.23Ni0.77 phase. The power annealed at temperature 500 results in forming of intermetallics AlFe3 and FeNi3 after 5h milling. The nanocrystalline intermetallic compound was obtained after 500h milling.


1970 ◽  
Vol 48 (13) ◽  
pp. 1955-1958 ◽  
Author(s):  
F. Natola ◽  
Ph. Touzain

Le diagramme de fusion du système K–K2O est obtenu par la technique de l'analyse thermique différentielle. La fusion du monooxyde de potassium K2O se manifeste à 646 + 5 °C. Des transformations cristallines réversibles de l'oxyde sont observées à 317, 372 et 446 °C. La dismutation de l'oxyde en peroxyde et métal apparait à une température approximativement égale à celle de la dernière des transitions. Le diagramme K–K2O comporte un eutectique à une température très proche de la température de fusion du potassium et une monotectie à 600 °C (concentration monotectique: 30.5 % atomique d'oxygène). Aucune existence de sous-oxyde n'est démontrée.The potassium–oxygen phase diagram has been determined up to the composition of K2O by the technique of differential thermal analysis. Potassium monoxide K2O melts at 646 ± 5 °C. Reversible transitions occur in solid K2O at 317, 372, and 446 °C. Disproportion of the monoxide into the peroxide and metal occurs at a temperature identical or very near to that of the last transition. The K–K2O eutectic melts at a temperature very close to the melting temperature of pure K (degenerate eutectic) and the monotectic at 600 °C (monotectic concentration: 30.5 oxygen atomic %). No evidence has been obtained that would indicate the existence of a lower oxide.


2015 ◽  
Vol 29 (31) ◽  
pp. 1550196 ◽  
Author(s):  
Y. M. Sun ◽  
W. Q. Yu ◽  
D. Long ◽  
Y. Zhang ◽  
Z. Hua

[Formula: see text] amorphous alloy was prepared by melt-spinning and annealed at various temperatures. The thermal property, microstructure and magnetic property were investigated by differential thermal analysis (DTA), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). The crystallization process of [Formula: see text] alloy is as follow: Amorphous [Formula: see text] residual amorphous [Formula: see text]-[Formula: see text]-[Formula: see text]-[Formula: see text] solid solution. Coercivity [Formula: see text] of [Formula: see text] alloy changes complexly, which abruptly deteriorates at 843 K and then softens with increasing annealing temperature [Formula: see text].


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.


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