NaF-NaBr-Na2MoO4 and KF-KCl-KBr ternary systems

Phase equilibria in the NaF-NaBr-Na₂MoO₄ and KF-KCl-KBr have been investigated by differential thermal and X-ray powder diffraction analyses. In the NaF-NaBr-Na₂MoO₄ system, a ternary eutectic and a ternary peritectic, melting and 506 and 570°C with specific enthalpy of melting of 241 and 328 kJ/kg, respectively, have been revealed. In the KF-KCl-KBr system, the existence of zonal solid solutions has been established; crystallization temperatures and melting enthalpies have been determined for samples of several compositions lying on a univariant line. Original Russian Text ? N.N. Verdiev, P.A. Arbukhanova, E.G. Iskenderov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 1, pp. 129–134.     

Ag2Se-Tl2Se-Bi2Se3 quasi-ternary system

The Ag₂Se-Tl₂Se-Bi₂Se₃ quasi-ternary system (system A) was studied using DTA, X-ray powder diffraction, microstructure examination, and microhardness measurements. TlBiSe₂-AgBiSe₂, AgTlSe-AgBiSe₂, AgTlSe-Bi₂Se₃, and Tl₂Se-AgBiSe₂ polytherms, isothermal sections at 500 and 800 K, and liquidus surface projection of system A were constructed. System A is congruently triangulated into the following subordinate triangles: Tl₂Se-AgTlSe-Tl₉BiSe₆ (I), AgTlSe-Tl₉BiSe₆-TlBiSe₂ (II), Ag₂Se-AgTlSe-TlBiSe₂ (III), Ag₂Se-AgBiSe₂-TlBiSe₂ (IV), and AgBiSe₂-TlBiSe₂-Bi₂Se₃ (V). Subsystems I, III, and V are ternary systems with three-phase eutectic equilibrium; system II has a three-phase eutectic, and system IV is characterized by several invariant and monovariant peritectic and eutectic equilibria. Primary crystallization and homogeneity fields were outlined, and the types and coordinates of invariant and monovariant equilibria in system A were determined. A characteristic feature of the title system is an extensive field of solid solutions between high-temperature cubic AgBiSe₂ and TlBiSe₂ phases; this field lies as a continuous belt along the AgBiSe₂-TlBiSe₂ quasibinary section and covers about one-fourth of the surface area of the triangular diagram of system A.     

Investigation of the LiF-LiBr-Li2SO4-Li2MoO4 quaternary system

Phase equilibria in the LiF-LiBr-Li₂SO₄-Li₂MoO₄ system have been investigated by differential thermal analysis. The eutectic composition has been determined (mol %): LiF, 13.3; LiBr, 62.0; Li₂SO₄, 15.4; and Li₂MoO₄, 9.3. The melting point is 415°C, and the ehthalpy of melting is 200 kJ/kg. Original Russian Text ? T.V. Gubanova, E.I. Frolov, E.G. Danilushkina, I.K. Garkushin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 6, pp. 1037–1042.     

CaF2对硅酸三钙的制备及其生物活性的影响

采用固相反应制备不同CaF掺量的生物活性硅酸三钙(3CaO·SiO22,C3S),并研究CaF2对C3S的制备及生物活性的影响.化学滴定、TGA/DTA、XRD、SEM和FTIR的分析结果表明,在煅烧过程中,CaF2有效的促进CaCO3的分解,并能形成低共熔化合物,促进C3S的形成;存急冷过程中,CaF2抑制CS晶型转变和分解,CaF2有效提高固相反应制备C§的纯度;模拟体液(SBD浸泡实验结果表明掺与小掺CaF2的C3s表面分别在1 d和3 d内诱导形成诱导磷厌石,这表明掺CaF2可以提高C3S的生物活性.     

Phase equilibria in the SrS-Ga2S3 system

In the SrS-Ga₂S₃ system, there exist two individual compounds: SrGa₂S₄ (a = 2.084 nm, b = 2.050 nm, c = 1.220 nm; congruent melting at 1530 K) and Sr₂Ga₂S₅ (a = 1.253 nm, b = 1.203 nm, c = 1.117 nm; peritectic melting at 1330 K); both are orthorhombic. We discovered a compound of composition Sr₄Ga₂S₇; this compound crystallizes in cubic system with the unit cell parameter a = 0.6008 nm, space group Pa3, and decomposes by a solid-phase reaction at 870 K. Eutectic compositions are 42 and 73 mol % Ga₂S₃; eutectic melting temperatures are 1210 and 1170 K, respectively. The SrS solubility in γ-Ga₂S₃ at 1070 K reaches 4 mol %.     

LiCl-LiBr-LiVO3 and LiCl-LiBr-Li2MoO4 ternary systems

Phase equilibria in the LiCl-LiBr-LiVO₃ and LiCl-LiBr-Li₂MoO₄ ternary systems have been investigated by differential thermal analysis. The following compositions have been revealed (mol %): eutectic in the LiCl-LiBr-LiVO₃ system (18.0% LiCl, 72.0% LiBr, and 10.0% LiVO₃) with a melting point of 464°C and specific enthalpy of melting of 213 kJ/kg, and a minimum in the LiCl-LiBr-Li₂MoO₄ system (27.0% LiCl, 48.0% LiBr, and 25.0% Li₂MoO₄) with a melting point of 444°C. The investigation of ternary systems including salts of alkali metals is of practical interest for chemical industry and metallurgy, where salt mixtures are used as fused electrolytes and heat carriers. Original Russian Text ? T.V. Gubanova, E.I. Frolova, I.K. Garkushin, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 7, pp. 1220–1223.     

Phase equilibria in the NaF-LiF-LaF3 system

The NaF-LiF-LaF₃ system was studied by differential thermal and X-ray powder diffraction analyses. In the system, there are two ternary invariant points, a eutectic (580 ± 2°C, 44.0 mol % NaF, 42.0 mol % LiF, 14.0 mol % LaF₃), and a peritectic (595 ± 2°C, 45.0 mol % NaF, 39.0 mol % LiF, 16.0 mol % LaF₃). The ternary peritectic point results from the intersection of the crystallization fields of LiF, LaF₃, and NaLaF₄.     

Phase diagrams of (R4N)2[Nd(NO3)5]-decane-n-octanol (n-butanol, n-decanol) liquid ternary systems

Phase diagrams on the mole fraction scale are presented for decane- (R₄N)₂[Nd(NO₃)₅]-n-octanol(n-butanol, n-decanol) (1–2–3) ternary liquid systems, where R₄N⁺ stands for trialkylbenzylammonium, at T = 298.15 K. The C₁₀H₂₂-(R₄N)₂[Nd(NO₃)₅] binary system is a two-phase liquid system. One phase (phase I) is the almost neat solvent; the other (phase II) is enriched in (R₄N)₂[Nd(NO₃)₅]. The liquid ternary systems are characterized by homogeneous and two-phase liquid solution fields. One phase is enriched in (R₄N)₂[Nd(NO₃)₅] and n-octanol (n-butanol, n-decanol) and the other in C₁₀H₂₂. The miscibilities in the C₁₀H₂₂-(R₄N)₂[Nd(NO₃)₅] binary system and in the ternary liquid systems were used to calculate, from the equations of the nonrandom two-liquid model (NTRL), intermolecular interaction parameters and excess Gibbs free energies g ^E for the binary and ternary liquid systems along the binodal curve. g ^E > 0 is characteristic of the systems under study, while g ^E decreases in the series of pairs of liquids (1, 2), (1, 3), and (2, 3) Original Russian Text ? A.K. Pyartman, V.A. Keskinov, P.V. Zaitsev, N.A. Charykov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 8, pp. 1392–1397.     

SnSbBiTe4-2Bi2Te3 join of the SnTe-Bi2Te3-Sb2Te3 quasi-ternary system

This is the first study of the SnSbBiTe₄-2Bi₂Te₃ join of the SnTe-Bi₂Te₃-Sb₂Te₃ quasi-ternary system by the methods of complex physicochemical analysis over a wide range of concentrations. A phase diagram was constructed for the title quasi-binary join. The system was found to be of the eutectic type; the eutectic coordinates are 65 mol % Bi₂Te₃ and 675 K. The starting components were shown to form solid solutions with extents of 20 mol %. Alloys with compositions lying within the Bi₂Te₃-based solid solution region were found to be n-type semiconductors.     

Phase diagram of the system CaF2-GdF3

A phase diagram of the system CaF₂-GdF₃ was studied by thermal and X-ray analysis. Two wide domains of solid solutions based on CaF₂ and a high-temperature modification of α-GdF₃ (LaF₃-structural type) are present in this system. Two maxima were found on the melting curves of the Ca_1?xGd_xF_2+x and α-(Gd_1?yCa_yF_3?y solid solutions, at 1428 ± 10? (5 mole % GdF₃) and 1282 ± 5? (85 mole % GdF₃), respectively. The coordinates of the eutectic are 60 mole % GdF₃ and 1233 ± 5?.

     

Phase diagram of the Pb5Sb4S11-Pb2SnSb2S6 system

The Pb₅Sb₄S₁₁-Pb₂SnSb₂S₆ system was studied by a number of physicochemical methods, and its phase diagram was constructed. It was found that the system under investigation is a quasi-binary eutectic type section of the SnS-PbS-Sb₂S₃ ternary system. The coordinates of the eutectic are found to be 33 mol % Pb₅Sb₄S₁₁ and 750 K. Regions of solid solutions based on Pb₅Sb₄S₁₁ (6 mol % Pb₂SnSb₂S₆) and Pb₂SnSb₂S₆ (4 mol % Pb₅Sb₄S₁₁) were determined.     

Phase diagrams for the binary systems CaCl2-KCl and CaCl2-CaCrO4

Phase diagrams have been determined using differential thermal analysis for the binary systems CaCl₂-KCl and CaCl₂-CaCrO₄. CaCl₂-KCl phase diagrams have been previously reported but results were not consistent. No prior studies have been reported for the CaCl₂-CaCrO₄ system. In the CaCl₂-KCl binary system two eutectics have been located at 24.0 mole % KCl (m.p. 615°C) and 74.3 mole % KCl (m.p. 594°C). A double salt of composition CaKCl3 melting congruently at 741°C has been found. The CaCl₂-CaCrO₄ system is a simple eutectic system with the eutectic occurring at 23.4 mole % CaCrO₄ and melting at 660°C.     

CaF2对CaO-CaF2-B2O3-SiO2：Sm2O3玻璃的光致发光增强效应

用高温熔融法制备了掺杂Sm₂O₃的CaO-CaF₂-B₂O₃-SiO₂(CFBS:Sm)发光玻璃材料, 并借助X射线衍射(XRD)谱、傅里叶变换红外(FTIR)光谱以及光致发光(PL)光谱等分析手段研究了玻璃基体中CaF₂的摩尔分数及其结构、红外透过性能以及荧光性能的关系. XRD和FTIR测试表明, 玻璃基体中引入CaF₂并未引起非晶结构的变化但其红外透过峰发生移动. 光谱学测试表明, CFBS:Sm发光玻璃在404 nm波长激发下出现对应于Sm³⁺离子位于566、603和650 nm的特征荧光峰, 其发光颜色为橙红色(x=0.531, y=0.371). 此外, 随着玻璃基体中CaF₂摩尔分数的增加, CFBS:Sm发光玻璃的荧光发射强度、荧光寿命(Sm³⁺的⁴G_5/2能级)和荧光量子效率也表现出增大的趋势. 这种CFBS:Sm发光玻璃中荧光发射强度和荧光寿命的提高主要是由于玻璃基体中的CaF₂替代CaO引起基体相互作用和声子能量降低、无辐射跃迁减弱造成的.     

Thermal analysis of the LiF-SrFCl-SrCO3 three-component system

Thermal analysis of the LiF-SrFCl-SrCO₃ system and its subsystems was carried out for the first time. In binary subsystems, incongruently melting compounds of compositions SrFCl · SrCO₃, 4SrFCl · SrCO₃, and LiF · SrCO₃ are formed; their crystallization volumes are closed by peritectic points. The thermoanalytical data were used to design planar and spatial phase diagrams, which illustrate the phase complex of the title system. The thermal properties of a eutectic melt were studied.     

超声化学法制备不同形貌的CaF2微米晶

采用超声化学法,以CaCl2与不同氟源(NaBF4、K2SiF6)在溶液中反应,制得了不同形貌的CaF2微米晶(立方体、花状、多面体)。用XRD、SEM及TEM对产物晶相及形貌进行了表征。XRD结果显示所有产物均为结晶良好的立方相CaF2。SEM及TEM结果表明由NaBF4制得的产物形貌为均匀的立方体微米晶,而由K2SiF6制得的产物为多面体。在添加配体Na2EDTA的情况下,由NaBF4得到的产物为纳米片组成的花状结构。本文详细讨论了氟源种类、反应物比例、配体等反应参数对产物CaF2形貌的影响,并提出了可能的反应机理。     

Interaction in the Ga2S3-Y2O2S system

The phase diagram of the Ga₂S₃-Y₂O₂S system has been investigated by differential thermal, X-ray powder diffraction, microstructural, and thermodynamic analyses. It has been established that the system is eutectic, and solubility at 295 K from the Ga₂S₃ side reaches 3 mol % Y₂O₂S. The coordinates of the eutectic point are 14 mol % Y₂O₂S and 1320 K.     

Directional crystallization of B4C-NbB2 and B4C-MoB2 eutectic compositions

We studied the directional crystallization of different compositions in B₄C-NbB₂ and B₄C-MoB₂ systems. The eutectic compositions for both systems are evaluated. It is shown that in the first system the rod-like eutectic structure is formed, in second, the “Chinese hieroglyphics”. In both cases high hardness and high microplasticity are observed, which are much more than for individual component phases. These compositions may be considered as a new kind of self-strengthening composite materials.     

Isomorphism in the (NH4)2Th(NO3)6-K2Th(NO3)6-Rb2Th(NO3)6 system

Syntheses were developed, and compounds of composition (NH₄)_2x K_2y Rb_2z Th(NO₃)₆(x + y + z = 1) were prepared. These compounds were structurally studied using X-ray diffraction and IR spectroscopy. Incomplete miscibility in the solid phase of the title system was found, and the impossibility of existence of a hexanitratothorate complex in the (NH₄)₂Th(NO₃)₆-K₂Th(NO₃)₆ system at 298.15 K and the component molar ratio 1: 3 was demonstrated. Calorimetric standard enthalpies of formation and mixing at 298.15 K were determined. Original Russian Text ? N.G. Chernorukov, A.V. Knyazev, A.A. Sazonov, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 7, pp. 1066–1071.     

Phase diagrams of some non-quasi-binary joins of the AlCl3-BiCl3-NaCl system

Phase diagrams of NaAlCl₄-(70.0 mol % AlCl₃ + 30.0 mol % BziCl₃), NaAlCl₄-(34.2 mol % AlCl₃ + 65.8 mol % BiCl₃), and (61.0 mol % AlCl₃ + 39.0 mol % NaCl)-AlCl₃ · BiCl₃ non-quasi-binary joins have been investigated using differential thermal and X-ray powder diffraction analyses. The fields of primary and joint crystallization of phases and invariant equilibrium temperatures have been determined in these joins. The structure of the joins has been confirmed by X-ray powder diffraction data. Original Russian Text ? N.I. Kaloev, A.A. Turieva, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 2, pp. 357–359.     

Interactions in the subsolidus region of the Na2MoO4-NiMoO4-Fe2(MoO4)3 system

Phase relations have been investigated in the subsolidus region of the Na₂MoO₄-NiMoO₄-Fe₂(MoO₄)₃ system by X-ray diffraction, differential thermal analysis, and vibrational spectroscopy. The phase of variable composition Na_1−x Ni_1−x Fe_1+x (MoO₄)₃(0≤x≤0.5) with the NASICON structure (space group R c) and the NaNi₃Fe(MoO₄)₅ ternary molybdate crystallizing in the triclinic crystal system (space group P ) have been obtained. A high conductivity was found in Na_1−x Ni_1−x Fe_1+x (MoO₄)₃, which allows one to consider this phase of variable composition as a promising solid electrolyte with sodium ion conduction. Original Russian Text ? N.M. Kozhevnikova, A.V. Imekhenova, 2009, published in Zhurnal Neorganicheskoi Khimii, 2009, Vol. 54, No. 4, pp. 695–700.