Phase equilibria in the ternary reciprocal system Li, Ba // BO2, F and growth of bulk β-BaB2O4 crystals

2017 ◽  
Vol 50 (1) ◽  
pp. 22-29 ◽  
Author(s):  
E. A. Simonova ◽  
A. E. Kokh ◽  
N. G. Kononova ◽  
V. S. Shevchenko ◽  
D. A. Kokh ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
Nonlinear Optical ◽  
Reciprocal System ◽  
Primary Crystallization ◽  
Primary Crystallization Field ◽  
Ternary Reciprocal System ◽  
X Ray ◽  
Visual Polythermal Analysis ◽  
Polythermal Sections ◽  
Phase Relationships

In order to find the optimum solvent for the growth of nonlinear optical β-BaB2O4 crystals, the phase relationships in the ternary reciprocal system Li, Ba // BO2, F have been studied using solid state synthesis, differential thermal analysis and X-ray powder diffraction. Isothermal and polythermal sections of the system Li, Ba // BO2, F are reported. In the studied system, the following compounds are formed: LiBa2B5O10 (melts by peritectic reaction at 930°C, i.e. 1203 K) and LiBaF3 (melts incongruently at 850°C, i.e. 1123 K). Visual polythermal analysis of seeding and growth of β-BaB2O4 crystals in this system was carried out. The primary crystallization field of β-BaB2O4 was defined. Using the top-seeded pulling technique, a β-BaB2O4 crystal of 93 mm in diameter, 34 mm in height and 520 g in weight has been grown.

Phase Assembly of Ti2SnC Powders

2011 ◽  
Vol 412 ◽  
pp. 187-190 ◽  
Author(s):  
Chun Long Guan ◽  
Guo Qin Liu ◽  
Ying Chun Shan
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Intermetallic Compounds ◽  
Single Phase ◽  
Reaction Path ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermediate Phases ◽  
Reaction Equations ◽  
Phase Relationships

Ti2SnC powders (Ti: Sn: C =2: 1.2: 1, mol.%) were synthesized by pressureless sintering in argon in the temperature range of 600 to 1050°C using Ti, Sn and graphite powders as the initial materials. The phase relationships during reaction in the ternary system Ti-Sn-C have been investigated. The products for identification and analysis were characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). The reaction path for the formation of Ti2SnC can be described in the following steps. Sn melted at 230°C, which provided a favorable liquid circumstance for the reactions between Ti and Sn to form Ti-Sn intermetallic compounds. Results showed that Ti6Sn5 and Ti5Sn3 intermediate phases were formed in turn with increase of temperature. Up to 1050°C, with consumption of Ti5Sn3 phases completely, the amount of Ti2SnC increased significantly. Single phase Ti2SnC with small amount of TiC was produced. Combined with the results of differential thermal analysis (DTA) and X-ray diffraction (XRD), it is revealed that Ti2SnC phase is formed by the reaction of Ti–Sn intermetallic compounds, Ti and graphite. In addition, the reaction equations of the process from 230 to 1050°C were given.

X-Ray Characterization of Phase Equilibria of the Raveau and 2212 Phases in the Bi-Sr-Ca-Cu-0 System

1995 ◽  
Vol 39 ◽  
pp. 731-738
Author(s):  
Winnie Wong-Ng ◽  
Lawrence P. Cook ◽  
F. Jiang
Keyword(s):  
Solid Solution ◽  
Phase Equilibria ◽  
Powder Diffraction ◽  
Primary Crystallization ◽  
Primary Crystallization Field ◽  
X Ray ◽  
Solid Solution Region ◽  
Ca Substitution ◽  
Solution Region

Phase equilibria of two superconductor phases, namely the 20K Raveau phase (Bi2.2-xSr1.8+xCuOz, currently referred to as the 11905 phase) and the 80K 2212 phase of the Bi-Sr-Ca-Cu-0 system were investigated. The amount of Ca-substitution of the Raveau solid solution was determined and the solid solution region can be approximately described as Bi2.2+xSr1.8-X-Y CayCu1±x/2Ow (referred to as the Ca-Raveau phase or the 119x5, ‘ with 0<x<0.15, 0<y<0.5. To determine the melting equilibria of the 2212 phase, a procedure involving the use of a wicking technique to capture the melt was applied. X-ray powder diffraction (XPD) and quantitative energy dispersive x-ray spectroscopy (EDS) were used to analyse the phases present in the residual and melt, respectively. The approximate primary crystallization field of the incongruently melting 2212 phase was illustrated.

Phase Formation Route of Cr2AlC Ceramics from Cr, Al and Graphite Powders

2010 ◽  
Vol 105-106 ◽  
pp. 192-194 ◽  
Author(s):  
Chun Long Guan ◽  
Guo Qin Liu ◽  
Ying Chun Shan
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Ternary System ◽  
Intermetallic Compounds ◽  
Single Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intermediate Phases ◽  
Reaction Equations ◽  
Phase Relationships

Cr2AlC ceramics (Cr:Al:C =1:1.2:1 mol.%) were synthesized by powder metallurgical method in argon in the temperature range of 700 to1250°C using Cr, Al and graphite powders as the initial materials. The phase relationships during reaction in the ternary system Cr-Al-C were investigated. The products were characterized by X-ray diffraction (XRD) and differential thermal analysis (DTA). It was found that Cr9Al17, Al8Cr5 and Cr2Al intermediate phases were formed in turn with increase of temperature. Up to 1050°C, with consumption of Cr9Al17 and Al8Cr5 phases completely, the amount of Cr2Al increased significantly. Single phase Cr2AlC with small amount of Cr7C3 was produced until 1250°C. Combined with the results of differential thermal analysis (DTA) and X-ray diffraction (XRD), it is revealed that Cr2AlC phase is formed by the reaction of Cr–Al intermetallic compounds, Cr, Al and graphite. In addition, the reaction equations of the process from 660 to1250°C were given.

The gold/selenium system and some gold seleno-tellurides

1968 ◽  
Vol 46 (16) ◽  
pp. 2637-2640 ◽  
Author(s):  
G. E. Cranton ◽  
R. D. Heyding
Keyword(s):  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Powder Diffraction ◽  
Ternary Phase ◽  
Stable Phase ◽  
Cell Content ◽  
X Ray ◽  
Space Groups ◽  
Liquid Phases ◽  
Phase Relationships

The phase relationships in the gold/selenium system have been examined using X-ray powder diffraction techniques and differential thermal analysis. Only one stable phase, α-AuSe, is formed. A metastable modification of this compound, β-AuSe, is also formed by reaction of the elements. Both forms are monoclinic:α-AuSe: space group C2, Cm, or C2/m; a = 12.21 ± 2, b = 3.693 ± 4, c = 8.434 ± 6 Å, β = 103.20 ± 3°; cell content, 8(AuSe).β-AuSe: primitive monoclinic (space groups P21 or P21/m are likely); a = 6.27 ± 1, b = 3.668 ± 4, c = 8.35 ± 1 Å, β = 105.95 ± 13°; cell content, 4(AuSe).Both modifications decompose peritectoidally at ca. 400 °C. Gold and selenium form a monotectic at 754 °C at a composition just above 50 at. % selenium; some evidence was obtained for the presence of two liquid phases above the monotectic.Tellurium does not substitute in the AuSe lattice to a detectable extent. However, a ternary phase which includes the composition Au2SeTe is formed. Au2SeTe is primitive orthorhombic with a = 8.924 ± 6, b = 7.56 ± 1, c = 5.741 ± 8 Å. The cell contains 4 formula units. Selenium will substitute for at least 15 at. % of the tellurium atoms in the monoclinic AuTe2 calaverite lattice at ca. 400 °C.

scholarly journals Phase relations in the Tl2 Te–TlBiТe2 –TlTbTe2 system

2021 ◽  
Vol 23 (1) ◽  
pp. 32-40
Author(s):  
Samira Z. Imamaliyeva ◽  
Ganira I Alakbarzade ◽  
Dunya M. Babanly ◽  
Marina V. Bulanova ◽  
Vagif A. Gasymov ◽  
...  
Keyword(s):  
Phase Equilibria ◽  
Solid Solutions ◽  
Solid Phase ◽  
Liquidus Surface ◽  
Primary Crystallization ◽  
Wide Field ◽  
Isothermal Sections ◽  
X Ray ◽  
Δ Phase ◽  
Polythermal Sections

The phase equilibria in the Tl2Te–TlBiТe2–TlTbTe2 concentration area of the Tl–Bi–Tb-Te quaternary system were investigated by using the differential thermal analysis and powder X-ray diffraction techniques. The diagram of the solid-phase equilibria of this system at room temperature was constructed. It was established that the Tl9BiTe6–Tl9TbTe6 section divides the Tl2Te–TlBiТe2–TlTbTe2 system into two independent subsystems. It was found that the Tl2Te–Tl9BiTe6–Tl9TbTe6 subsystem is characterized by the formation of a wide field of solid solutions with a Tl5Te3 structure (δ-phase) that occupy more than 90% of the area of the concentration triangle. The results of X-ray phase analysis of alloys of the Tl9BiTe6–Tl9TbTe6–TlTbTe2–TlBiТe2 subsystem showed the formation of wide regions of solid solutions based on TlTbTe2 and TlBiTe2 along the section of TlTbTe2–TlBiTe2 ((β1- and β2-phases) and made it possible to determine the location of the heterogeneous phase regions in this subsystem. The parameters of crystal lattices of mutually saturated compositions of the β1-, β2-, and δ-phases are calculated from powder diffraction patterns.The paper also presents some polythermal sections, isothermal sections at 740 and 780 K of the phase diagram, as well as projections of the liquidus and solidus surfaces of the Tl2Te–Tl9BiТe6–Tl9TbTe6 subsystem. The liquidus surface consists of three fields of the primary crystallization of α (Tl2Te)-, δ- and β1-phase. The constructed isothermal sections clearly demonstrate that the directions of the tie lines do not coincide with the T–x planes of the studied internal sections, which is characteristic of non-quasi-binary polythermal sections. The obtained new phases are of interest as potential thermoelectric and magnetic materials.

Phase Relationships and Phase Formation in the System BaF2-BaO-Y2O3-CuOx-H2O

2001 ◽  
Vol 689 ◽  
Author(s):  
W. Wong-Ng ◽  
L. P. Cook ◽  
J. Suh ◽  
I. Levin ◽  
M. Vaudin ◽  
...  
Keyword(s):  
Reaction Kinetics ◽  
Phase Formation ◽  
Volume Fraction ◽  
Reciprocal System ◽  
Ex Situ ◽  
Coated Conductor ◽  
X Ray Diffraction ◽  
X Ray ◽  
Phase Relationships

ABSTRACTThe interplay of melting equilibria and reaction kinetics is important during formation of the Ba2YCu3O6+x (Y-213) phase from starting materials in the quaternary reciprocal system Ba,Y,Cu//O,F. For experimental investigation of the process we used a combination of differential thermal analysis (DTA) for study of melting equilibria, and in-situ high-temperature x-ray diffraction (HTXRD) for study of the phase formation and reaction kinetics. DTA investigation of compositions spaced along compositional vectors extending from the oxide end to the fluoride end of the reciprocal system have given evidence of low melting liquids (∼600 °C) near the fluorine-rich end. Work is continuing to determine whether similar thermal events observed in the interior of the system also indicate low temperature liquids, and on the extent to which low-melting liquids could be involved in Y-213 phase formation. HTXRD investigations have been initiated on the conversion of 0.3 μm and 1.0 μm thick BaF2-Y-Cu precursor films to Y-213 in the presence of water vapor. Preliminary results indicated that the thickness of film has a strong influence on the texture of the Y-213 film: a 0.3 μm film showed mainly (001) texture, whereas a 1.0 μm film showed a greater volume fraction of (h00) texture. While the HTXRD method cannot directly reveal the presence of liquid, we are working to combine DTA and HTXRD data for a unified picture of Y-213 phase formation during the “BaF2 ex-situ” process for coated-conductor fabrication.

PENINGKATAN LAJU DISOLUSI ACYCLOVIR DENGAN METODE SISTEM DISPERSI PADAT MENGGUNAKAN POLOXAMER 188

2016 ◽  
Vol 5 (1) ◽  
pp. 6
Author(s):  
Budi Setiawan ◽  
Erizal Zaini ◽  
Salman Umar
Keyword(s):  
Electron Microscopy ◽  
Thermal Analysis ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Differential Thermal Analysis ◽  
Fourier Transform Infrared ◽  
X Ray Diffraction ◽  
Poloxamer 188 ◽  
X Ray ◽  
Scanning Electron

Sebuah penelitian tentang sistem dispersi padat dari asiklovir dengan poloxamer 188 telah dilakukan formulasi dengan pencampuran secara fisika dengan rasio 1 : 1, 1 : 3, 1 : 5 dan dispersi padat 1 : 1, 1 : 3, 1 : 5 dan penggilingan 1:1 sebagai pembanding. Dispersi padat dibuat menggunakan metode pencairan (fusi), yang digabung dengan poloxamer 188 pada hotplate kemudian asiklovir dimasukkan ke dalam hasil poloxamer 188 lalu di kocok hingga membentuk masa homogen. Semua formula yang terbentuk termasuk asiklovir poloxamer 188 murni dianalisis karakterisasinya dengan Differential Thermal Analysis (DTA), X-ray Diffraction, Scanning Electron Microscopy (SEM), dan Fourier Transform Infrared (FTIR), kemudian pengambilan dilakukan  (penentuan kadar) mengunakan spektrofotometer UV pada panjang gelombang 257,08 nm dan uji laju disolusi dengan aquadest bebas CO2 menggunakan metode dayung. Hasil pengambilan  (penentuan kadar) menunjukkan bahwa semua formula memenuhi persyaratan farmakope Amerika edisi 30 dan farmakope Indonesia edisi 4 yaitu 95-110%. Sedangkan hasil uji laju disolusi untuk campuran fisik 1: 1, dan dispersi padat 1: 1, dan penggilingan 1: 1 menunjukkan peningkatan yang nyata dibandingkan asiklovir murni. Hal ini juga dapat dilihat dari hasil perhitungan statistik  menggunakan analisis varian satu arah  SPSS 17.

Interaction of ditertiary phosphines with phenyl- and 1-naphthyldithiocarbamatonickel(II)

1985 ◽  
Vol 50 (6) ◽  
pp. 1383-1390
Author(s):  
Aref A. M. Aly ◽  
Ahmed A. Mohamed ◽  
Mahmoud A. Mousa ◽  
Mohamed El-Shabasy
Keyword(s):  
Thermal Analysis ◽  
Powder Diffraction ◽  
Spin Structure ◽  
Magnetic Measurements ◽  
Mixed Ligand ◽  
Mixed Ligand Complexes ◽  
X Ray ◽  
Square Planar

The synthesis of the following mixed ligand complexes is reported: [Ni(phdtc)2(dpm)2], [Ni(phdtc)2(dpe)2], [Ni(phdtc)2(dpp)3], [Ni(1-naphdtc)2(dpm)2], [Ni(1-naphdtc)2], and [Ni(1-naphdtc)2(dpp)2], where phdtc = PhNHCSS-, 1-naphdtc = 1-NaPhNHCSS-, dpm = Ph2PCH2PPh2, dpe = Ph2P(CH2)2PPh2, and dpp = Ph2P(CH2)3PPh2. The complexes are characterised by microanalysis, IR and UV-Vis spectra, magnetic measurements, conductivity, X-ray powder diffraction, and thermal analysis. All the mixed ligand complexes are diamagnetic, and thus a square-planar or square-pyramidal (low-spin) structure was proposed for the present complexes.

scholarly journals Struvite Grown in Gel, Its Crystal Structure at 90 K and Thermoanalytical Study

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 89 ◽  
Author(s):  
Jolanta Prywer ◽  
Lesław Sieroń ◽  
Agnieszka Czylkowska
Keyword(s):  
Thermal Analysis ◽  
Sodium Metasilicate ◽  
X Ray Diffraction ◽  
Gel Growth ◽  
Growth Technique ◽  
Thermoanalytical Study ◽  
X Ray ◽  
Cell Parameters ◽  
Thermal Analysis Techniques ◽  
Derivative Thermogravimetry

In this article, we report the crystallization of struvite in sodium metasilicate gel by single diffusion gel growth technique. The obtained crystals have a very rich morphology displaying 18 faces. In this study, the habit and morphology of the obtained struvite crystals are analyzed. The crystals were examined and identified as pure struvite by single X-ray diffraction (XRD). The orthorhombic polar noncentrosymmetric space group Pmn21 was identified. The structure of the crystal was determined at a temperature of 90 K. Our research indicates a lack of polymorphism, resulting from the temperature lowering to 90 K, which has not been previously reported. The determined unit cell parameters are as follows a = 6.9650(2) Å, b = 6.1165(2) Å, c = 11.2056(3) Å. The structure of struvite is presented here with a residual factor R1 = 1.2% at 0.80 Å resolution. We also present thermoanalytical study of struvite using thermal analysis techniques such as thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA).

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