Zur Chemie von Mischphasen in komplexen Zustandsdiagrammen Das System Bi2O3/Bi2Se3/Bi2Te3/Chemistry of Mixed Crystals in Complex Phase Diagrams The System Bi2O3/Bi2Se3/Bi2Te3

2000 ◽  
Vol 55 (7) ◽  
pp. 627-637 ◽  
Author(s):  
P. Schmidt ◽  
H. Oppermann
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Phase Diagrams ◽  
Thermodynamic Modeling ◽  
Solid Solutions ◽  
Thermodynamic Data ◽  
Phase Relations ◽  
Mixed Crystals ◽  
Complex Phase ◽  
Quaternary Solid Solution

Abstract Pseudoternary System Bi2O3/Bi2Se3/Bi2Te3, Phase Diagram, Thermodynamic Data The phase diagram of the pseudoternary system Bi2O3/Bi2Se3/Bi2Te3 is found to include a quaternary solid solution Bi2O2 (TexSe1-x) and ternary, intermetallic mixed crystals Bi2(TexSe1-x)3. Using thermodynamic modeling of the solid solutions it is possible to calcu­ late complex heterogeneous equilibria between all phases of this phase diagram. As a result we can thermodynamically describe the observed phase relations:Bi2(TexSe1-x)3 ⊿H°m(298) = 0; ⊿S°m(298) = R[xlnx + (1-x)ln(1-x)]Bi2O2(TexSe1-x) ⊿H°m(298) = Ω · x(1-x); O⊿S°m(298) = R/4 [xlnx + (1-x)ln(1-x)]Ω = 0,6 kcal/mol

Phase Equilibria in the System NaAlSi3O8–NaAlSiO4–H2O with Special Emphasis on the Stability of Analcite

1971 ◽  
Vol 8 (3) ◽  
pp. 311-337 ◽  
Author(s):  
Ki-Tae Kim ◽  
B. J. Burley
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Phase Diagrams ◽  
Solid Solutions ◽  
Singular Points ◽  
Phase Relations ◽  
The Other ◽  
Stability Field ◽  
Narrow Zone ◽  
The Stability

Phase equilibria were determined in the P–T range of 0.5–10 Kb and 150–900 °C in the system NaAlSi3O8 – NaAlSiO4 – H2O. Two isobaric (2 Kb and 5.15 Kb) T–X phase diagrams (projected to a dry base) were completely determined and show that the stability field of analcite solid solutions has a large distorted pentagonal shape. The phase relations for the transition: nepheline hydrate I [Formula: see text] nepheline + H2O on the composition join NaAlSiO4 – H2O are not binary. It was found that there exists a narrow zone for the transition. The true P–T curve was found and determined in terms of a ternary univariant reaction: nepheline hydrate I + analcite [Formula: see text] nepheline + H2O. In the system NaAlSi3O8 – SiO2 – H2O, albite contains about 5 wt % silica in solid solution at 5.15 Kb and 670 °C.The equilibrium compositions of various univariant phases were determined essentially on the basis of the T–X phase diagrams. Another univariant reaction (zeolite species P = analcite + nepheline – hydrate I + H2O) was found at 2 Kb/215 °C and 5.15 Kb/235 °C and determined on a P–T projection. Three singular points were determined; two of them are located at 0.8 Kb/390 °C and 9.4 Kb/475 °C respectively on a univariant P–T curve for the reaction nepheline hydrate I + analcite = nepheline + H2O; the other one is located at 6 Kb/655 °C on a univariant P–T curve along which nepheline, analcite, liquid, and vapor coexist. The petrogenetic implication of analcite is discussed fully.

Electron microprobe study of turquoise-group solid solutions in the Neyshabour and Meydook mines, northeast and southern Iran

2020 ◽  
Vol 58 (1) ◽  
pp. 71-83
Author(s):  
Elahe Mansouri Gandomani ◽  
Nematollah Rashidnejad-Omran ◽  
Amir Emamjomeh ◽  
Pietro Vignola ◽  
Tahereh Hashemzadeh
Keyword(s):  
Solid Solution ◽  
Solid Solutions ◽  
Electron Microprobe ◽  
Electron Probe Microanalysis ◽  
Electron Probe ◽  
Major Elements ◽  
Point Of View ◽  
Chemical Compositions ◽  
Light Blue ◽  
Quaternary Solid Solution

ABSTRACT Turquoise, CuAl6(PO4)4(OH)8·4H2O, belongs to the turquoise group, which consists of turquoise, chalcosiderite, aheylite, faustite, planerite, and UM1981-32-PO:FeH. In order to study turquoise-group solid solutions in samples from the Neyshabour and Meydook mines, 17 samples were selected and investigated using electron probe microanalysis. In addition, their major elements were compared in order to evaluate the feasibility of distinguishing the provenance of Persian turquoises. The electron microprobe data show that the studied samples are not constituted of pure turquoise (or any other pure endmember) and belong, from the chemical point of view, to turquoise-group solid solutions. In a turquoise–planerite–chalcosiderite–unknown mineral quaternary solid solution diagram, the chemical compositions of the analyzed samples lie along the turquoise–planerite line with minor involvement of chalcosiderite and the unknown mineral. Among light blue samples with varying hues and saturations from both studied areas, planerite is more abundant among samples from Meydook compared with samples from Neyshabour. Nevertheless, not all the light blue samples are planerite. This study demonstrates that distinguishing the deposit of origin for isochromatic blue and green turquoises, based on electron probe microanalysis method and constitutive major elements, is not possible.

Quaternary phase diagrams as a tool for ionic cocrystallization: the case of a solid solution between a racemic and enantiopure ionic cocrystal

CrystEngComm ◽  
2020 ◽  
Vol 22 (14) ◽  
pp. 2537-2542
Author(s):  
Lixing Song ◽  
Fucheng Leng ◽  
Koen Robeyns ◽  
Tom Leyssens
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Phase Diagrams ◽  
Solid Solution Formation ◽  
Quaternary Phase ◽  
Solution Formation ◽  
Contour Lines

Quaternary phase diagram of ionic cocrystals with solid solution formation is generated and dissolution surface is depicted clearly by contour lines.

Spinel solid solutions in the systems MgAl2O4–ZnAl2O4 and MgAl2O4–Mg2TiO4

1997 ◽  
Vol 12 (10) ◽  
pp. 2584-2588 ◽  
Author(s):  
M. A. Petrova ◽  
G. A. Mikirticheva ◽  
A. S. Novikova ◽  
V. F. Popova
Keyword(s):  
Solid Solution ◽  
Phase Diagrams ◽  
Melting Temperature ◽  
Solid Solutions ◽  
Spinel Structure ◽  
Room Temperature ◽  
Binary Systems ◽  
Continuous Series ◽  
X Ray ◽  
Spinel Solid Solutions

Phase relations in two binary systems MgAl2O4–ZnAl2O4 and MgAl2O4–Mg2TiO4 have been studied and phase diagrams for them have been constructed. Based on the data of x-ray phase and crystal-optical analyses, the formation of a continuous series of solid solutions with spinel structure between the terminal members of the systems studied has been established. In the MgAl2O4–ZnAl2O4 system the solid solution is stable in the range from room temperature to melting temperature. In the MgAl2O4–Mg2TiO4 system the solid solution decomposes below 1380 °C, yielding the formation of limited regions of homogeneity on the basis of MgAlM2O4 and Mg2+2δ Ti1–δO4. Decomposition of the solid solution is accompanied by crystallization of MgTiO3.

scholarly journals Phase equilibria in the YFeO3 – YСoO3 system in air

2021 ◽  
Vol 8 (1) ◽  
pp. 20218108
Author(s):  
A. V. Bryuzgina ◽  
A. S. Urusova ◽  
I. L. Ivanov ◽  
V. A. Cherepanov
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Phase Equilibria ◽  
Spin State ◽  
Solid Solutions ◽  
Homogeneity Range ◽  
Perovskite Structure ◽  
Single Phase ◽  
Decomposition Temperature ◽  
Unusual Behavior

YFe1-xСоxO3 solid solutions were prepared by glycerol-nitrate technique. The homogeneity range of solid solutions was studied within the temperature range 1173 – 1573 K. A continues series of solid solution below the decomposition temperature of YСоO3, which was shown to be equal to 1266 ± 6 K, begins to narrow at higher temperatures and becomes equal to 0 ≤ x ≤ 0.1 at 1573 K. The phase diagram of the YFeO3 – YСoO3 system in the “T – composition” coordinates was divided into three fields. Similar to the parent ternary oxides, all single-phase YFe1-xСоxO3 solid solutions possess orthorhombically distorted perovskite structure (Pnma space group). Unusual behavior of orthorhombic distortions in YFe1-xСоxO3 with temperature was explained by probable changes in spin state of Co3+ ions.

The Na+, K+/CN-, I- binary systems

1990 ◽  
Vol 55 (7) ◽  
pp. 1741-1749
Author(s):  
Milan Drátovský ◽  
Bohumír Grüner ◽  
Ivan Horsák ◽  
Jiří Makovička
Keyword(s):  
Phase Diagram ◽  
Binary System ◽  
Phase Diagrams ◽  
Solid Solutions ◽  
Binary Systems ◽  
Smoothing Spline ◽  
Spline Functions ◽  
Solidus Curve

The phase diagram of the KCN-KI binary system was measured and the published phase diagrams of the KCN-NaCN, NaI-KI and NaCN-NaI systems were verified and completed. The systems form solid solutions with minima on the liquidus and solidus curves. The solid solutions in the KCN-KI system probably have a high segregation temperature, close to the solidus curve. For the four binary systems the experimental points were fitted with liquidus and solidus curves either by applying smoothing spline functions or by using two different models. The results obtained are discussed.

scholarly journals Акустические аномалии в твердых растворах SrTiO-=SUB=-3-=/SUB=--BiFeO-=SUB=-3-=/SUB=-

2018 ◽  
Vol 60 (1) ◽  
pp. 107
Author(s):  
Е. Смирнова ◽  
А. Сотников ◽  
Н. Зайцева ◽  
H. Schmidt
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Dielectric Constant ◽  
Solid Solutions ◽  
Solution System ◽  
Temperature Range ◽  
Relaxor State ◽  
Solid Solution System ◽  
Pulse Echo ◽  
Pulse Echo Method

AbstractThe results of acoustic investigations of solid solutions SrTiO_3−BiFeO_3 in the temperature range from 100 to 650 K have been presented. The measurements of the velocity and attenuation of the longitudinal ultrasonic mode at a frequency of 10 MHz were carried out by the pulse-echo method. The observed anomalies in velocity and attenuation correlate with the maxima of the dielectric constant in the temperature range of the relaxor state. In addition, the attenuation peaks in the temperature range 400–600 K, which define Burns and T* temperatures, which are characteristic of relaxors, have been identified. The obtained results have allowed the clarifying of the phase diagram of the solid solution system SrTiO_3−BiFeO_3.

scholarly journals STUDY OF THE CU3AS4TE9-CRASTE3 SECTION OF THE AS2Te3-Cr2Te3-CuTe quasi-ternary system

2021 ◽  
pp. 40-44
Author(s):  
S. Ismailova
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Ternary System ◽  
Solid Solutions ◽  
Room Temperature ◽  
Physicochemical Analysis ◽  
Binary Section ◽  
Quasi Binary Section ◽  
Quasi Ternary System

Chemical interactions in the system were studied by methods of physicochemical analysis (DTA, XRD, MSA, determination of density and microhardness) and its phase diagram was constructed. It was found that the phase diagram of the system is a non-quasi-binary section of the quasi-ternary system As2Te3-Cr2Te3-CuTe. At room temperature in the system of solid solutions based on Cu3As4Te9 reaches - 5 mol. % CrAsTe3. The region of the solid solution based on the CrAsTe3 compound has not been established in practice. The dependence of the microhardness and density of alloys of the Cu3As4Te9-CrAsTe3 system on the composition has been investigated.

scholarly journals Effects caused by antiferroelectric nanodomains in PZT-based coarse-grained ceramics with compositions from the morphotropic boundary region

2017 ◽  
Vol 07 (01) ◽  
pp. 1750005 ◽  
Author(s):  
V. M. Ishchuk ◽  
D. V. Kuzenko ◽  
V. L. Sobolev
Keyword(s):  
Phase Diagram ◽  
Solid Solution ◽  
Solid Solutions ◽  
Lead Zirconate Titanate ◽  
Lead Zirconate ◽  
Boundary Region ◽  
Coarse Grained ◽  
Solid Solution Decomposition ◽  
Zirconate Titanate ◽  
Coexisting Phases

Presented results demonstrate importance of taking into account such a phenomenon as the solid solution decomposition at the boundaries separating coexisting phases in lead zirconate-titanate-based solid solutions with compositions belonging to the morphotropic boundary region of the “temperature–composition” phase diagram. It is shown that in the local decomposition of solid solutions in the vicinity of the boundaries separating the tetragonal and rhombohedral phases in lead zirconate-titanate-based solid solutions lead to the changes of the solid solution’s chemical composition and to the formation of segregates. It is also shown that the proper thermoelectric treatment of samples containing these segregates can give substantially higher values of piezoelectric parameters in the lead zirconate-titanate-based compounds.

scholarly journals Phase diagram determination and thermodynamic modeling of the Cu-Mg-Si system

2016 ◽  
Vol 52 (1) ◽  
pp. 99-112 ◽  
Author(s):  
J. Zhao ◽  
J. Zhou ◽  
S. Liu ◽  
Y. Du ◽  
S. Tang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Phase Diagram ◽  
Thermodynamic Modeling ◽  
Phase Relationship ◽  
Powder Metallurgy Method ◽  
X Ray Diffraction ◽  
Complex Phase ◽  
X Ray ◽  
Ternary Compounds ◽  
Measured Phase

13 ternary Cu-Mg-Si alloys were prepared by means of the powder metallurgy method. Phase equilibria at 500 and 700 oC of the Cu-Mg-Si system were determined using X-ray diffraction analysis (XRD). The existence of 3 ternary compounds in this system was verified: CuMgSi_Sigma (Cu16Mg6Si7), Tau (Cu3Mg2Si), and Laves ((Cu0.8Si0.2)2(Mg0.88Cu0.12)). A thermodynamic modeling for the Cu-Mg-Si system was then conducted on the basis of the experimental data obtained in this work and those critically reviewed from the literature. The complex phase relationship between Laves phase and other phases has been successfully modeled in this work. Comparisons between the calculated and the measured phase diagrams show that most of the experimental data can be reproduced by the presently obtained thermodynamic parameters.

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