The Silver–Calcium System

1971 ◽  
Vol 49 (8) ◽  
pp. 1315-1316 ◽  
Author(s):  
A. N. Campbell ◽  
W. H. W. Wood
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Powder Diffraction ◽  
Composition Range ◽  
X Ray ◽  
Good Agreement

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.

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
Keyword(s):  
Thermal Analysis ◽  
Phase Diagram ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Phase Diagrams ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Large Field ◽  
X Ray ◽  
Crucial Difference

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.

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.

High-Temperature Modifications of Thorium Dicarbide

1964 ◽  
Vol 8 ◽  
pp. 78-85 ◽  
Author(s):  
P. K. Gantzel ◽  
S. Langer ◽  
N. L. Baldwin ◽  
F. L. Kester
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
High Temperature ◽  
Thermal Effects ◽  
Room Temperature ◽  
Thermal Analyses ◽  
Tetragonal Modification ◽  
X Ray ◽  
Space Groups ◽  
Heating And Cooling

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.

Synthesis and Characterization of Ti, Fe-Doped Mullite-I

2011 ◽  
Vol 217-218 ◽  
pp. 163-168 ◽  
Author(s):  
Lin Xin Tong ◽  
Jin Hong Li ◽  
Jian Cao
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Separation ◽  
Powder Diffraction ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Formation Temperature ◽  
Gel Method ◽  
X Ray

A series of gels with 3Al2O3•2SiO2 were prepared by Sol-gel method and heated at several temperatures for 2 h to synthesize Ti, Fe-doped mullite. The powers were characterized by differential thermal analysis (DSC-TG) and X-ray powder diffraction (XRD). Phase separation was promoted by doping both TiO2 and Fe2O3; with increasing the amount of dopant ions the formation temperature of Si-Al spinel decreased and the formation temperature of mullite increased by TiO2 doping but decreased by Fe2O3 doping. The formation temperature of pure mullite was about 1250-1350 °C.

scholarly journals The devitrification of PbO-B2O3-ZnO glass doped with Li2O

2000 ◽  
Vol 65 (12) ◽  
pp. 891-898 ◽  
Author(s):  
Vladimir Zivanovic ◽  
Nikola Blagojevic ◽  
Snezana Grujic ◽  
Ljiljana Karanovic ◽  
Branislava Bozovic
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Phase Composition ◽  
Powder Diffraction ◽  
Crystalline Phase ◽  
Crystallization Behavior ◽  
X Ray ◽  
Crystallization Ability ◽  
Lower Temperature ◽  
Xrpd Analysis

In this paper the effect of the addition of Li2O on the crystallization behavior of PbO-B2O3-ZnO glass was investigated by the differential thermal analysis (DTA) and X-ray powder diffraction (XRPD) methods. The crystallization ability, as well as the crystalline phases which develop during devitrification of the glass were examined. The results of DTA and XRPD analysis showed that the addition of Li2O varies the sequence of the crystallization as well as the phase composition of the crystalline phase. The glasses with Li2O crystallize at a lower temperature (360?C) with 4Li2O.4ZnO.3B2O3 as the major crystalline phase. The base PbO-B2O3-ZnO glass crystallizes at 480?C with PbO.2ZnO.B2O2 as the major crystalline phase.

Phase relations of the Ce2Co17–Sm2Co17 pseudo-binary system

2020 ◽  
Vol 111 (5) ◽  
pp. 373-378
Author(s):  
Chengfu Xu ◽  
Zhengfei Gu ◽  
Yongquan Yang ◽  
Dongdong Ma ◽  
Gang Cheng ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Powder Diffraction ◽  
Solid Solutions ◽  
Vertical Section ◽  
Analysis Data ◽  
Phase Relations ◽  
Differential Thermal Analysis Data ◽  
Pseudobinary System ◽  
X Ray

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.

Investigations on the Thermal Decomposition of Coordination Polymers Based on Copper(I) Halides and 2-Methylpyrazine

2001 ◽  
Vol 56 (10) ◽  
pp. 997-1002 ◽  
Author(s):  
Chnstian Näther ◽  
Inke Jeß ◽  
Harald Studzinski
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Differential Thermal Analysis ◽  
Thermal Behaviour ◽  
Powder Diffraction ◽  
Coordination Polymers ◽  
Intermediate Phase ◽  
Compound I ◽  
X Ray

The thermal behaviour of the three coordination polymers 2∞poly[CuX(μ-2-methylpyrazine- N,N′)] (X = Cl (I), Br (II)), and 2∞poly[{Cu2l2 (μ-pyrazine-N,N′)2 } · 2-methylpyrazine] (III) was investigated using differential thermal analysis and thermogravimetry (DTA-TG) measurements as well as temperature resolved X-ray powder diffraction in argon and in air. On heating all compounds decompose in two steps. In the first step compound I and II loose one and compound III looses two of the 2-methylpyrazine ligands to form the corresponding 2:1 compounds Cu2Cl2(2 -methylpyrazine) (IV) and 2∞poly[Cu2X2 (μ-2 -methylpyrazine-N,N′)] (X = Br (V), I (VI)). From the experiments there is no evidence for the formation of a 1:1 compound of Cul and 2-methylpyrazine as an intermediate phase during the thermal decomposition. On further heating the 2:1 compounds IV, V and VI transform directly to the corresponding copper(I) halides.

The CdO–CdF2 system: X-ray diffractogram, infrared spectrum, and density of CdO•2CdF2

1970 ◽  
Vol 48 (10) ◽  
pp. 1619-1622 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Infrared Spectrum ◽  
Powder Diffraction ◽  
Heat Absorption ◽  
X Ray

The CdO–CdF2 system has been studied by differential thermal analysis (DTA), X-ray powder diffraction, and infrared spectroscopy.The results show a distinct X-ray diffractogram and infrared spectrum for the CdO–CdF2 mole ratio 1:2, prefused and annealed, suggesting the existence of the compound CdO•2CdF2. The compound undergoes a transformation at 690 °C, characterized by a low heat absorption suggesting an order–disorder phenomenon.

Sol-Gel Derived Mullite-Gahnite Composite

2014 ◽  
Vol 87 ◽  
pp. 126-131
Author(s):  
Stanislav Kurajica ◽  
Emilija Tkalčec ◽  
Vilko Mandić ◽  
Iva Lozić ◽  
Jörg Schmauch
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Powder Diffraction ◽  
Sol Gel ◽  
Intermediate Formation ◽  
X Ray ◽  
Thermal Reactions ◽  
Sol Gel Process ◽  
Crystal Phases ◽  
Crystallization Path

Mullite-gahnite composites with different phase-proportions were prepared using sol-gel process. Crystallization path was determined using differential thermal analysis (DTA). X-ray powder diffraction (XRD) was used to study the crystal phases development. The course of the thermal reactions is dominated by the intermediate formation of two spinel phases. The former phase was attributed to gahnite, while the latter to Al-Si spinel. Zn loading decreases amounts of mullite and α-alumina, while increases gahnite and amorphous phase. The observed microstructure of sintered bodies is characterized by fine gahnite particles distributed among larger mullite grains, which is highly favourable for ceramics with high mechanical requirements.

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