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1.
The subsolidus region of the Ag2MoO4-MgMoO4-Al2(MoO4)3 ternary salt system has been studied by X-ray phase analysis. The formation of new compounds Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 (0 ≤ x ≤ 0.4) and AgMg3Al(MoO4)5 has been determined. The Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 variable-composition phase is related to the NASICON type structure (space group R \(\bar 3\) c). AgMg3Al(MoO4)5 is isostructural to sodium magnesium indium molybdate of the same formula unit and crystallizes in triclinic system (space group P \(\bar 1\), Z = 2) with the following unit cell parameters: a = 9.295(7) Å, b = 17.619(2) Å, c = 6.8570(7) Å, α = 87.420(9)°, β = 101.109(9)°, γ = 91.847(9)°. The compounds Ag1 ? x Mg1 ? x Al1 + x (MoO4)3 and AgMg3Al(MoO4)5 are thermally stable up to 790 and 820°C, respectively. 相似文献
2.
The subsolidus phase composition of the M2O-CdO-V2O5 systems with M = Li or Na is studied. Double orthovanadates MCdVO4 and MCd4(VO4)3 form solid solutions of composition Li1 ? 2x/3Cd x/3CdVO4 (0 ≤ x ≤ 1, orthorhombic space group Cmcm, modulation at x = 0.6) and Na3 ? 2x Cd3 + x (VO4)3 (0 ≤ x ≤ 0.10 and 0.30 ≤ x ≤ 1, orthorhombic space group Cmcm and Pn21 a or Pnma, respectively). In the range 0.10 < x < 0.30, the end-members of the solid solutions coexist. Isothermal sections of the systems are mapped. 相似文献
3.
B. G. Bazarov O. D. Chimitova R. F. Klevtsova Yu. L. Tushinova L. A. Glinskaya Zh. G. Bazarova 《Journal of Structural Chemistry》2008,49(1):53-57
A ternary salt system Rb2MoO4-Eu2(MoO4)3-Hf(MoO4)2 was studied in the subsolidus area by X-ray phase analysis. A novel ternary molybdate, Rb4.98Eu0.86Hf1.11(MoO4)6, formed in the system. The Rb4.98Eu0.86Hf1.11(MoO4)6 rubidium-europium-hafnium molybdate crystals were grown by solution-melt crystallization under the spontaneous nucleation conditions. The structure and composition of this compound were refined by single crystal X-ray diffraction (X8 APEX automated diffractometer, MoK α radiation, 1753 F(hkl), R = 0.0183). The crystals are trigonal, a = b = 10.7264(1) Å, c = 38.6130(8) Å, V = 3847.44(9) Å3, Z = 6, space group R \(\bar 3\) c. The three-dimensional mixed framework of the structure comprises Mo tetrahedra and two types of octahedra, (Eu,Hf)O6 and HfO6. The large cavities of the framework include two types of the rubidium atom. The distribution of the Eu3+ and Hf4+ cations over two crystallographic positions was refined. 相似文献
4.
A continuous solid solution LaMn1?y Cr y O3 with an orthorhombic structure is found to exist in the range of 0.0 ≤ y ≤ 1.0. An orthorhombic solid solution La1?x Sr x CrO3 exists in the range of 0.0 ≤ x ≤ 0.1. The stability boundaries are determined for the perovskite phase La1?x Sr x Mn1?y Cr y O3. An isobaric-isothermal section LaMnO3-SrMnO3-SrCrO4-LaCrO3 of the system La2O3-SrO-Mn3O4-Cr2O3 in air at 1100°C is designed. 相似文献
5.
K. S. Gavrichev N. N. Smirnova M. A. Ryumin V. M. Gurevich A. V. Tyurin L. N. Komissarova F. M. Spiridonov V. P. Danilov 《Russian Journal of Inorganic Chemistry》2007,52(10):1607-1611
Adiabatic calorimetry is used to measure the low-temperature heat capacity of Na2Er(MoO4)(PO4)from 6.41 to 347.87 K. Experimental data are used to calculate the thermodynamic functions of Na2Er(MoO4)(PO4), which at 298.15 K are as follows: C p 0 (298.15 K) = 243,3 ± 0.4 J/(K mol), S 0(298.15 K) = 312.8 ± 0.8 J/(K mol), H 0(298.15 K) ? H 0(0 K) = 45280 ± 90 J/mol, and Φ0(298.15 K) = 136.1 ± 0.3 J/(K mol). A diffuse heat-capacity anomaly associated with splitting of the Stark levels (Schottky anomaly) is discovered in the low-temperature region. 相似文献
6.
K. S. Gavrichev N. N. Smirnova A. V. Khoroshilov M. A. Ryumin V. M. Gurevich A. V. Tyurin G. A. Sharpataya L. N. Komissarova V. P. Danilov 《Russian Journal of Inorganic Chemistry》2007,52(5):727-732
The low-temperature heat capacity of Na2Lu (MoO4)(PO4) was measured by adiabatic calorimetry in the range of 7.47–345.74 K. The experimental data were used to calculate the thermodynamic functions of Na2Lu (MoO4)(PO4). At 298.15 K, the following values were obtained: C p 0 (298.15 K) = 237.7 ± 0.1 J/(K mol), S 0(298.15 K) = 278.1 ± 0.8 J/(K mol), H 0(298.15 K) ? H 0 (0 K) = 42330 ± 20 J/mol, and Φ0(298.15 K) = 136.1 ± 0. 3 J/(K mol). A heat capacity anomaly was found in the range of 10-67 K with a maximum at T tr = 39.18 K. The entropy and enthalpy of transition are ΔS = 12.39 ± 0.75 J/(K mol) and ΔH = 403 ± 16 J/mol. The thermal investigation of sodium lutetium molybdate phosphate in the high-temperature range (623–1223 K) was performed using differential scanning calorimetry. It was found that during melting in the range of 1030–1200 K, Na2Lu(MoO4)(PO4) degrades to simpler compounds; the degradation scenario is verified by X-ray powder diffraction. 相似文献
7.
V. L. Volkov N. V. Podval’naya E. G. Volkova 《Russian Journal of Inorganic Chemistry》2009,54(3):350-355
The phase and chemical compositions of the precipitates formed in the LiVO3-VOSO4-H2O system at initial pH within 1 ≤ pH ≤ 4 and 90°C were studied. The following phases were prepared: an α phase Li1.4(VO)1.3[H2V10O28] · nH2O and a β phase Li0.6 ? x H1.4 + x [V12O31 ? y/2] · nH2O (0 ≤ x ≤ 0.5, 1.3 ≤ y ≤ 2.0) with a layered structure. Li0.4V2O5 · H2O nanorods with the interlayer distance 10.30 ± 0.08 Å were synthesized at 180°C in an autoclave. The morphology, IR spectra, and main formation processes for these polyvanadates were studied. 相似文献
8.
S. Y. Yang S. Zhang B. L. Fu Q. Wu F. L. Liu C. Deng 《Journal of Solid State Electrochemistry》2011,15(11-12):2633-2638
A series of Cr-doped Li3V2???x Cr x (PO4)3 (x?=?0, 0.1, 0.25, and 0.5) samples are prepared by a sol–gel method. The effects of Cr doping on the physical and chemical characteristics of Li3V2(PO4)3 are investigated. Compared with the XRD pattern of the undoped sample, the XRD patterns of the Cr-doped samples have no extra reflections, which indicates that Cr enters the structure of Li3V2(PO4)3. As indicated by the charge–discharge measurements, the Cr-doped Li3V2???x Cr x (PO4)3 (x?=?0.1, 0.25, and 0.5) samples exhibit lower initial capacities than the undoped sample at the 0.2 C rate. However, both the discharge capacity and cycling performance at high rates (e.g., 1 and 2 C) are enhanced with proper amount of Cr doping (x?=?0.1). The highest discharge capacity and capacity retention at the rates of 1 and 2 C are obtained for Li3V1.9Cr0.1(PO4)3. The improvement of the electrochemical performance can be attributed to the higher crystal stability and smaller particle size induced by Cr doping. 相似文献
9.
B. G. Bazarov R. F. Klevtsova A. E. Sarapulova K. N. Fedorov L. A. Glinskaya Zh. G. Bazarova 《Journal of Structural Chemistry》2005,46(4):756-760
Single crystals of triple molybdate of composition 5:1:3 K5Pb0.5Hf1.5(MoO4)6 have been grown and their crystal structure has been solved from X-ray diffraction data (an automated diffractometer X8 APEX, MoK α -radiation, 2173 F(hkl), R = 0.0321). Trigonal unit cell parameters are: a = b = 10.739(2) Å, c = 37.933(9) Å; V = 3789(1) Å3, Z = 6, ρcalc = 4.014 g/cm3, space group \(R\bar 3\). Three-dimensional mixed framework of the structure is formed by two types of MoO4 tetrahedra and Pb and Hf octahedra linking via common O-vertices. Potassium atoms of three types occupy large vacancies in the framework. 相似文献
10.
The title compound (disodium dipotassium copper(II) tris-[molybdate (VI)]) is prepared by form melt and characterized by single crystal X-ray diffraction and UV-vis spectroscopy. It crystallizes in the triclinic space group P-1 with a = 7.4946(8) Å, b = 9.3428(9) Å, c = 9.3619(9) Å, α = 92.591(7)°, β = 105.247(9)°, γ = 105.496(9)°, V = 604.7 Å3, and Z = 2. Its structure is isotypic with that of Na4Mn(MoO4)3. It is formed by Cu2O10 distorted bi-octahedral dimers linked by two bridging bidentate Mo2O4 tetrahedra and, additionally, two monodentate Mo1O4 tetrahedra to form Cu2Mo4O20 units. These units are linked by the insertion of Mo3O4 tetrahedra to build infinite ribbons disposed along the c axis. All of these ribbons form a one-dimensional framework. Both K1 and K3 cations are located in the inversion center, and all the other atoms are at general positions. The structure model is supported by the bond valence sum (BVS) and charge distribution CHARDI methods. The Cu2+ cations adopt the [4+2] CuO6 Jahn-Teller distortion giving rise to an intense d–d transition in the UV-vis absorption spectra. 相似文献
11.
G. V. Bazuev T. I. Chupakhina M. A. Lelkozerova 《Russian Journal of General Chemistry》2008,78(10):1843-1848
Attempts of the synthesis in air of complex oxides Sr3RhMnOx and Sr4Rh1.5Mn1.5Ox resulted in revealing formation of a new oxide phase Sr6.3Rh2.35Mn2.35O9 related to quasi-unidimensional family A3n+3m A′ n B3m+n O9m+6n at n = 1 and m = 1. Its structural characteristics and magnetic properties are studied. X-ray data of the obtained phase is indicated on the basis of trigonal cell (spatial group P321) with the parameters: a 9.6239(4) Å; c 1 4.1130(4) Å, c 2 2.4946(2) Å. Manganese and rhodium exist in the compound as the cations Mn4+, Rh3+ and Rh4+, as follows from the data of measuring of magnetic susceptibility in the range 2–300 K. 相似文献
12.
V. A. Nadolinnyi N. V. Chernei A. V. Sinitsyn A. A. Pavlyuk S. F. Solodovnikov 《Journal of Structural Chemistry》2008,49(5):859-864
The binary molybdate Li2Zn2(MoO4)3 of a new crystal type was characterized by EPR, optical spectroscopy, and X-ray diffraction methods. The crystals have the Pnma symmetry group and the lattice parameters a = 5.1139(5) Å, b = 10.4926(13) Å, c = 17.6445(22) Å; Z = 4. The crystals possess scintillation properties; emission is caused by the presence of impurity levels in the forbidden band. The EPR studies of the nature of the impurity centers responsible for the scintillation characteristics of the crystal showed that the centers were Cu2+ ions substituted for zinc ions in the oxygen octahedra. The directions of the main values of the g and tensors (g zz , A zz ) correspond to the direction of O-Cu-O of the oxygen octahedron distorted along the Z axis. The EPR spectra of the copper ions are described by the spin Hamiltonian with the parameters g ‖ = 2.38, g ⊥ = 2.06; A ‖ = 116 G, A ⊥ = 0 G. 相似文献
13.
L. T. Denisova A. D. Izotov L. A. Irtyugo Yu. F. Kargin V. M. Denisov V. V. Beletskii 《Doklady Physical Chemistry》2016,466(1):4-7
The heat capacities of Pb2V2O7 and Pb3(VO4)2 as a function of temperature in the range 350–965 K have been studied by the differential scanning calorimetry method. The CP = f(T) curve for Pb2V2O7 is described by the equation Cp = (230.76 ± 0.51) + (73.60 ± 0.50)×10-3T ? (18.38 ± 0.54)×105T-2 in the entire temperature range. For Pb3(VO4)2, there is a well-pronounced extreme point in the CP = f(T) curve at T = 371.5 K, which is caused by the existence of a structural phase transition. The thermodynamic properties of the oxide compounds have been calculated. 相似文献
14.
M. G. Zuev 《Russian Journal of Inorganic Chemistry》2007,52(3):424-426
The phase composition has been studied and an equilibrium phase diagram has been designed for the Al2O3-Li2O-R2O5 (R = Ta or Nb) systems in the subsolidus region up to 1000°C and 85 mol % Li2O. New phases with the composition Li1+x Al1?x O2?x , where x = 0–0.67, have been found. 相似文献
15.
Vertical sections CaF2-Na0.4Yb0.6F2.2 and NaF-Ca0.75Yb0.25F2.25 of the system NaF-CaF2-YbF3 were studied by differential thermal analysis. A fluorite solid solution belt between phases of variable composition Ca1?x Yb x F2+x and Na0.5?x Yb0.5+x F2+2x was discovered. A liquidus-surface projection was constructed. The solidification character of the solid solution is unfavorable for growth of optical-quality ternary mixed crystals. 相似文献
16.
I. V. Korolkov S. A. Gromilov K. V. Yusenko I. A. Baidina S. V. Korenev 《Journal of Structural Chemistry》2005,46(6):1052-1059
The [Ir(NH3)5Cl]2[OsCl6]Cl2 binary complex salt has been prepared, and its structure was investigated by single crystal X-ray diffraction. Crystal data: a = 11.1901(13) Å, b = 7.9138(13) Å, c = 13.4384(18) Å; β = 99.640(3)°, V = 1190.0(2), space group C2/m, Z = 2, FW = 1099.47, d x = 3.068 g/cm3. Thermolysis products of [Ir(NH3)5Cl]2[OsCl6]Cl2, [Ir(NH3)5Cl][OsBr6], (NH4)2[OsCl6]x[IrCl6]1?x , and K2[OsCl6]x[IrCl6]1?x were studied by X-ray phase analysis; the unit cell parameters were refined, and the dependence of volume per atom (V/Z) on the composition of the Ir Os1?x solid solution has been plotted. 相似文献
17.
A. R. Zaripov V. A. Orlova V. I. Pet’kov O. M. Slyunchev D. D. Galuzin S. I. Rovnyi 《Russian Journal of Inorganic Chemistry》2009,54(1):45-51
The new phosphate Cs2Mn0.5Zr1.5(PO4)3 was synthesized for the first time and characterized by X-ray diffraction. Its crystal structure was refined in space group P213, Z = 4 at 25°C (a = 10.3163(1) Å, V = 1097.93(1) Å3), by the Rietveld method using the powder X-ray diffraction data. The structure is built of an octahedral-tetrahedral framework {[Mn0.5Zr1.5(PO4)3]2?}3∞ with cesium atoms being located in large cavities. The hydrolytic stability of the powdered phosphate containing 137Cs radionuclide was studied. The minimum achieved 137Cs leaching rate was 4 × 10?8 g/cm2 day. 相似文献
18.
V. A. Nadolinny A. A. Ryadun V. N. Shlegel’ N. V. Ivannikova 《Journal of Structural Chemistry》2016,57(4):665-669
The article presents the results of EPR studies of Pb2MoO5 crystals containing a copper impurity. Based on the analysis of angular dependences of the EPR spectra, it is found that copper ions incorporate into the structure of the Pb2MoO5 crystal in the Cu2+ state and occupy the molybdenum site with the formation of a linear extended Cu(II)–V(O)–Pb(IV) defect along the а axis of the crystal. An oxygen vacancy appears in the structure of the defect to compensate the charge and the lead ion acquires the Pb4+ charge state. According to the structure of this center, one magnetically non-equivalent position with the direction of main values of А and g of A(Cu)zz and gzz tensors parallel to the а axis is observed in the EPR spectra. Moreover, the EPR spectra exhibit an addition hyperfine structure from one lead atom on which the unpaired electron density is 0.061%. The obtained data on the structure of the defect formed when the copper impurity incorporates into the Pb2MoO5 crystal provided the assumption that the observed light scattering when the light beam is directed perpendicular to the а axis may be due to the cooperative effect of the presence of di- and tetravalent ions substituting for molybdenum in the linear configuration of Pb–O–Mo bonds. 相似文献
19.
A. Yu. Ledneva N. G. Naumov A. V. Virovets S. Cordier Y. Molard 《Journal of Structural Chemistry》2012,53(1):132-137
The structures of three novel octahedral rhenium cluster compounds [Re6S8(CN)2(py)4]·H2O (1), [Re6S8(CN)2(4-Mepy)4] (2), [Re6S8(CN)2(4-Mepy)4]·4-Mepy (3) (py = pyridine, 4-Mepy = 4-methylpyridine) are determined by X-ray crystallography. Crystal data are: C2/m space group, a = 14.813(1) Å, b = 14.772(1) Å, c = 9.2122(6) Å, β = 119.085(2)°, V = 1761.7(2) Å3, d x = 3.318 g/cm3, R = 0.0585 (1); I41/amd space group, a = 16.0018(3) Å, c = 14.7186(5) Å, V = 3768.81(16) Å3, d x = 3.169 g/cm3, R = 0.0489 (2); P21/c space group, a = 9.0452(4) Å, b = 15.8065(7) Å, c = 15.2951(6) Å, β = 103.700(2)°, V = 2124.57(16) Å3, d x = 2.957 g/cm3, R = 0.0245 (3). Molecular cluster complexes interact via π-π stacking affording 3D frameworks in 1 and 2 and chains in 3. 相似文献
20.
N. A. Kochetova I. E. Animitsa A. Ya. Neiman 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2009,83(2):203-208
(Ba1 ? x Ca x )6Nb2O11 solid solutions were synthesized. The compositions were shown to be single-phase at 0.23 ≤ x ≤ 0.47 and have a double perovskite cubic structure with an incomplete oxygen sublattice. The interaction of solid solutions with water vapor and their electrical properties were studied. In dry atmosphere, these complex oxides were mixed oxygen-hole conductors. In humid atmosphere, they intercalated water and exhibited protonic conductivity. The influence of Ba/Ca isovalent substitution, the dynamics of the oxygen sublattice, and the concentration of intercalated water on the value and contribution of protonic and hole conductivity was analyzed. 相似文献