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1.
Component interactions in the Cs2CdBr4-Cs2ZnBr4-CsBr ternary system have been studied by differential thermal analysis and X-ray powder diffraction. The liquidus surface is comprised of three crystallization fields: CsBr, a solid solution of Cs2CdBr4 with Cs2ZnBr4 (??), and a Cs3ZnBr5-based solid solution (??). The ternary eutectic coordinates are as follows: ??53.5 mol % Cs2CdBr4, 1.5 mol % Cs2ZnBr4, 45 mol % CsBr, and ??450°C. A Cs2CdBr4-Cs3ZnBr5 triangulating section, which is characterized by peritectic interaction with peritectic (p) coordinates of 20 mol % Cs3ZnBr5 and 480°C, divides the Cs2CdBr4-Cs2ZnBr4-CsBr ternary system into two ternary systems: Cs2CdBr4-CsBr-Cs3ZnBr5 and Cs2CdBr4-Cs3ZnBr5-Cs2ZnBr4.  相似文献   

2.
The interaction of components in the Cs2HgBr4-Cs2ZnBr4-CsBr ternary system was studied by differential thermal and X-ray powder diffraction analyses. The liquidus surface consists of the crystallization fields of three phases: CsBr, a solid solution of Cs2HgBr4 with Cs2ZnBr4 (??), and solid solution ?? based on Cs3ZnBr5. The ternary eutectic near Cs2HgBr4 has the coordinates ??83 mol % Cs2HgBr4, 2 mol % Cs2ZnBr4, and 15 mol % CsBr and the melting point ??415°C. The triangulating section Cs2HgBr4-Cs3ZnBr5 is characterized by the eutectic interaction with the eutectic that is degenerate near Cs2HgBr4, contains ??3 mol % Cs3ZnBr5, and melts at 420°C. This section divides the Cs2HgBr4-Cs2ZnBr4-CsBr ternary system into two ternary systems Cs2HgBr4-CsBr-Cs3ZnBr5 and Cs2HgBr4-Cs3ZnBr5-Cs2ZnBr4.  相似文献   

3.
The interaction in the HgBr2-CdBr2-PbBr2 ternary system was studied by differential thermal analysis; the isoconcentration section of the system at 50 mol % CdBr2 was investigated. Based on the results of the study, a projection of the liquidus surface of the HgBr2-CdBr2-PbBr2 ternary system to the composition triangle was constructed; the boundaries of the primary crystallization fields were determined for three phases: HgBr2 (degenerate field), solid solution α based on CdBr2, and solid solution β based on PbBr2; and isotherms were drawn. A ternary eutectic has the composition 93 mol % HgBr2-1 mol % CdBr2-6 mol % PbBr2 and melts at 235°C.  相似文献   

4.
Component interactions in the CsBr—Cs2ZnBr4—Cs2CdBr4—Cs2HgBr4 system were studied using differential thermal analysis (DTA) and powder X-ra y diffraction. The system is characterized by a continuous solid solution series. New compounds have not been found.  相似文献   

5.
Several vertical sections are investigated in the HgBr2-PbBr2-CsBr system by the methods of physicochemical analysis. Six compounds, namely, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6, are formed in the bordering binaries of the ternary system. By the results of investigation, the projection of the liquidus surface of the HgBr2-PbBr2-CsBr system on the composition triangle is constructed, and the fields of primary crystallization of nine phases are plotted, namely, HgBr2, PbBr2, CsBr, CsHg2Br5, CsHgBr3, Cs2HgBr4, CsPb2Br5, CsPbBr3, and Cs4PbBr6. An immiscibility region is found in the system. This region occupies a considerable part of the primary crystallization field of PbBr2. The coordinates of invariant points are determined, and isotherms are plotted.  相似文献   

6.
The sections Li2MCl4?4xBr4x of the quaternary systems LiCl-LiBr-MCl2-MBr2 with M = Mn, Cd, and Fe were studied by high-temperature X-ray diffraction patterns and DTA and DSC measurements. In the quasibinary lithium manganese halide system complete series of solid solutions exist between the inverse spinels Li2MnCl4 and Li2MnBr4. Li2MnBr4 and solid solutions with x > 0.54 undergo phase transitions to tetragonal spinels at lower temperatures. In the nonquasibinary system with M = Cd, only at temperatures near 400°C a complete series of mixed crystals is formed. At lower temperatures the system is mainly two-phase with rock salt-type Li1?yCd0.5yCl1?xBrx and cadmium chloride-type Cd1?yLi2yCl2?2xBr2x solid solutions in equilibrium. The lithium iron halide system is similar to that of cadmium, but spinel-type Li2FeBr4 does not exist at any temperature. The manganese and cadmium halide spinels and spinel solid solutions undergo phase transitions to NaCl defect structures at elevated temperatures.  相似文献   

7.
Glass formation is studied along the CsHgBr3-CsPbBr3, Cs2HgBr4-CsPbBr3, and CsHg2Br5-CsPbBr3 sections of the HgBr2-PbBr2-CsBr ternary system. The glass formation region is demarcated. Characteristic temperatures are determined by differential thermal analysis; the ratio T g/T m and the Hruby factor H R for glassy samples are determined. The data are analyzed, and the most promising glass compositions along the specified sections are determined.  相似文献   

8.
The solubility isotherms of the three-component systems: ZnBr2? H2O? C2H5OH and CdBr2? H2O? C2H5OH at 25°C have been studied. Crystallization fields of the equilibrium coexistence of the salts ZnBr2 · 2H2O, ZnBr2, CdBr2 · 4H2O, CdBr2 and CdBr2 · 1.5 C2H5OH in water-ethanol solvent have been found. The dehydration processes of crystalline hydrates and the probable solvation of Zn2+ and Cd2+ ions in the saturated solutions have been discussed.  相似文献   

9.
Two ranges of solid solutions were prepared in the system Li4SiO4Li3VO4: Li4?xSi1?xVxO4, 0 < x ? 0.37 with the Li4SiO4 structure and Li3+yV1?ySiyO4, 0.18 ? y ? 0.53 with a γ structure. The conductivity of both solid solutions is much higher than that of the end members and passes through a maximum at ~40Li4SiO4 · 60Li3VO4 with values of ~1 × 10?5 ohm?1 cm?1 at 20°C, rising to ~4 × 10?2 ohm?1 cm?1 at 300°C. These conductivities are several times higher than in the corresponding Li4SiO4Li3(P,As)O4 systems, especially at room temperature. The solid solutions are easy to prepare, are stable in air, and maintain their conductivity with time. The mechanism of conduction is discussed in terms of the random-walk equation for conductivity and the significance of the term c(1 ? c) in the preexponential factor is assessed. Data for the three systems Li4SiO4Li3YO4 (Y = P, As. V) are compared.  相似文献   

10.
Phase Relationship of the Quasibinary System NiCr2S4? ;NiGa2S4, Crystal Structure of NiGa2S4 The quaternary system NiCr2–2xGa2xS4 was studied with the help of X-ray powder Guinier photographs of quenched samples. The crystal structure of ternary NiGa2S4, not found formerly, was determined using single crystal data. The structure (trigonal space group P3 m1, Z = 1, a = 362.49(2), c = 1199.56(5) pm) consists of hexagonal close-packed sulfur with Ni and Ga in one fourth of the octahedral and tetrahedral holes, respectively (FeGa2S4 type). The S? ;S distance of the S? ;Ni? ;S layered units is unusually small, vic. 321.1 pm. The infrared spectrum of NiGa2S4 and a group theoretical treatment of the FeGa2S4 type lattice modes are given. Up to 20 mol % Ga of the layered NiGa2S4 can be substituted by Cr whereby Ni is possibly transfered from octahedral to tetrahedral sites. The phase width of monoclinic Cr3S4 type NiCr2S4 is very small possibly due to the metal-metal interaction in this NiAs defect structure. In the range 0.18 ? x ? 0.35 quaternary spinel type mixed crystals are formed.  相似文献   

11.
The NaCl-NaBO2-Na2CO3-Na2MoO4 quaternary system was studied by a calculation-experimental method and differential thermal analysis. The coordinates of one ternary eutectic and two quaternary eutectics were determined: E 7: 572°C, 29 mol % NaCl, 10 mol % NaBO2, 32 mol % Na2CO3, and 29 mol % Na2MoO4; ɛ1: 562°C, 36 mol % NaCl, 10 mol % NaBO2, 30.5 mol % Na2CO3, and 23.5 mol % Na2MoO4; and ɛ2: 536°C, 17 mol % NaCl, 10 mol % NaBO2, 27 mol % Na2CO3, and 46 mol % Na2MoO4.  相似文献   

12.
Correction of the Crystal Structure of “Cs4PbO3” and the Structural Relationship between the Modifications of Cs4PbO4 The compound that has been described as Cs4PbO3 really is Cs4PbO4. It does not crystallize in the space group P21, as assumed, but in P21/c. The observed fictitiuous violation of the extinction law for the c glide plane is due to twinning. The structure was refined using the original data as well as new data from an untwinned crystal. The denomination β-Cs4PbO4 is used to distinguish this structure from another known modification (α-Cs4PbO4). Both structures, α-Cs4PbO4 and β-Cs4PbO4, can be derived from the sphere packing of γ-plutonium when certain voids in its packing are occupied with oxygen atoms.  相似文献   

13.
Solid solutions based on CsFeO2 in Cs2 ? 2x Fe2 ? x A x O4 systems (A = P, V) were synthesized. Their crystal structure and the temperature and concentration dependences of the total conductivity and its electronic component were studied. The ranges of temperature and composition in which cesium-cation conductivity was dominant were determined. The obtained data were compared with the results of studies of other cesium-conducting solid electrolytes.  相似文献   

14.
A novel quaternary mixed halogenide, Tl5Hg2Br5I4, was synthesized by fusion of thallium bromide and mercury iodide in a 5:2 molar ratio. The crystal structure of Tl5Hg2Br5I4 represents a new series of composite structures described by the general formula nTlBr*mTl2[HgBr2I2]; in this case, n = 4 and m = 8. Electronic structure calculations indicate that the title compound is a semiconductor.  相似文献   

15.
Phase equilibria in the LiCl–LiBr–Li2SO4 ternary system and the LiCl–LiBr–Li2SO4–Li2MoO4 quaternary system were studied by differential thermal analysis. The compositions and temperatures of minima in the ternary and quaternary systems were determined to be (31.2 mol % LiCl, 46.8 mol % LiBr, 22.0 mol % Li2SO4, 460°C) and (25.2 mol % LiCl, 30.2 mol % LiBr, 14.6 mol % Li2SO4, 30.0 mol % Li2MoO4, 411°C), respectively.  相似文献   

16.
The First Fluoride A2[PtF6] of the K2PtCl6 Type: β-Cs2[PtF6] For the first time, yellow cubic single crystals of Cs2[PtF6] have been obtained by solid state reaction, heating (Pt-tube, 35 d, 800°C) the fluorination product of an intimate mixture of (NH4)2PtCl6 and 2 CsCl (diluted F2, F2:N2 = 1:5, 10 d, 400°C). The new form is isostructural with K2PtCl6: Fm3 m; a = 905.5(2) pm; Z = 4 (Guinier-de Wolff data, CuKα1); R = 2.32% (SHELX-76); 1398 I0(hkl), Image-Plate diffractometer data (Stoe IPDS). It is compared with already known α-Cs2[PtF6] (K2GeF6-type, P3 m1). The Madelung-Part of Lattice Energy, MAPLE, Effective Coordination Numbers, ECoN, and Mean Fictive Ionic Radii, MEFIR, are calculated and discussed in comparison with the data of further Hexafluoroplatinates(IV). A complete analysis of MAPLE was carried out for the title compound as well as for the α- and a hypothetical α′-form.  相似文献   

17.
Rémi D. Bergougnant 《Tetrahedron》2007,63(44):10751-10757
The macrocycle 4-tert-butylcalix[8]arene (L) was reacted with alkali metal carbonates (Li2CO3, Na2CO3, K2CO3, Rb2CO3, and Cs2CO3) at the interface of a biphasic THF/water system. Needle-like crystals with a general formula [Ax(4-tert-butylcalix[8]arene-xH)(THF)y(H2O)z] (with A=Li, Na, K, Rb, Cs, x=1, 2, y=4, 5, 8, and z=6, 7) were thereby obtained. The solid state structures were investigated by X-ray diffraction of single crystals and by TGA measurements. They do not appear to be maintained in solution.  相似文献   

18.
The phase equilibrium in the LiCl-LiBr-LiVO3-Li2MoO4 quaternary system was studied by differential thermal analysis. The composition corresponding to the minimum in the curve of monovariant equilibria of the quaternary system was determined to be 10.6 mol % LiCl, 38.0 mol % LiBr, 30.3 mol % LiVO3, and 21.1 mol % Li2MoO4, with the melting point at 389°C.  相似文献   

19.
Spinel compounds of the composition Fe1+xCr2?xS4, with 0 ≦ x ≦ 0.5, have been prepared in polycrystalline form. The ionic distribution Fe2+[Cr3+2?xFe3+x]S2?4 is derived from both X-ray and 57Fe Mo¨ssbauer data. Room temperature Mo¨ssbauer spectra show the typical behavior of tetrahedral-site Fe2+ surrounded by different octahedral-site neighbors. Octahedral-site Fe3+ absorbs as a doublet with Δ ≈ 0.5 mm/s. Samples of overall composition FeCr2S4 consist mainly of a spinel Fe2+[Cr3+2?yFe3+y]S2?4, y ≈ 0.02.  相似文献   

20.
Chemistry and Structural Chemistry of Phosphides and Ployphosphides. 44. Tricesium Heptaphosphide Cs3P7: Preparation, Structure, and Properties Tricesium heptaphosphide is prepared from the elements by a quantitative reaction at 1200 K in Nb ampoules. Slow cooling yield the bright yellow α-Cs3P7, quenching the yellow orange coloured β-Cs3P7. The crystalline α-Cs3P7 transforms at 552 K in a first order phase transition to the plastically crystalline β-Cs3P7. Both modifications are sensitive against moisture and oxygen and are completely soluble in ethylendiamine yielding a pale yellow solution. At room temperature the 31P nmr spectra of such solutions show only one singulett, which corresponds to the valence tautomerism of the P73? anion. α-Cs3P7 crystallizes in a new structure type (P41, a = 904.6(1) pm; c = 1671.4(4) pm; Z = 4). The structure is formed by heptaphospha-nortricyclene anions P73? and Cs+ cations. The cs atoms connect the anions forming a three-dimensional arrangement (d?(Cs? P) = 374 pm), not allowing the fragmentation into discrete Cs3P7 units. The P? P distances differ by their function in the nortricyclene anion. Each P7 group is surrounded by 12 Cs atms. β-Cs3P7 crystallizes in the Li3Bi type of structure (Fm3 M; a(573 K) = 1130.5(1)pm; Z = 4). The P atoms of the P73? anions surround the Bi positions with an orienational disorder. The orientation has been investigated with a mixed crystal Ca3(P7)2/3(P11)1/2 (Fm3 m; a (298 K) = 1149.5(9) pm; Z = 4).  相似文献   

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