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1.
《Journal of solid state chemistry》1987,71(1):61-69
The first systematic survey of the BaOReRe2O7 phase diagram is reported, with emphasis on the reduced ternary oxides. At 800°C, the previously reported compounds Ba3Re2O9, Ba2ReO5, and Ba3ReO6 were observed, all of which contain Re(VI) in ReO6 octahedra. The stability of these phases is apparently due to ReO π-bonding in and between the octahedra. The previously unknown structure of Ba2ReO5 was determined by powder neutron diffraction and found to be isotypic with that of K2VO2F3 (space group Pnma), with a = 7.3233(2), b = 5.7745(1), and c = 11.4124(2), Å. ReO6 octahedra share adjacent corners to produce cis chains which are held together by 10 coordinated Ba atoms. 相似文献
2.
《Journal of solid state chemistry》1986,63(2):129-138
Two new oxyborate compounds were synthesized during a study of the phase relationships between the pinakiolite-ludwigite series of compounds. The structural topologies of these previously unreported materials have been determined experimentally by comparing calculated with observed electron microscope images. Both of these structures are very similar to each other, and also closely related to pinakiolite which consists of flat walls of edge-sharing octahedra connected to zigzag chains of octahedra by triangular BO3 groups. The two new structures contain similar infinite walls which are separated by slabs of octahedra that are wider than the zigzag chains found in pinakiolite. A new series of structurally related oxyborate compounds can be envisaged and are described. 相似文献
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4.
《Journal of the Less Common Metals》1987,127(1):183-191
The excess enthalpies of the liquid alloys GaGeTe and GaSnTe were measured in a heat-flow calorimeter at 1203 K. The enthalpy surface in the ternary space in both systems is characterized by a valley stretching from the exothermic minimum in the GaTe system to the minima of the GeTe and SnTe systems. The minima in the ternary systems were found in this valley, i.e. on the sections Ga2Te3-GeTe and Ga2Te3-SnTe. A comparison of the experimental data with those calculated from the excess enthalpies of the constituent binaries with the aid of the Bonnier model, reveals only small deviations. A preliminary investigation was made into the ternary phase diagram of GaSnTe. This system contains the two quasibinary sections Ga2Te3-SnTe, GaTe-SnTe and the ternary compound Ga6SnTe10. The previously reported compounds Ga2SnTe3 and GaSnTe2 do not exist. 相似文献
5.
NdFeB and corresponding MmFeB compounds were studied, the high field magnetization at 4.2 K, the a.c. susceptibility (4.2 < T < 300 K) and the anisotropy field were measured using the singular point detection technique (77 < T < 570 K). At room temperature the anisotropy field of the MmFeB is about 3T, whereas that of NdFeB compounds is about 7T. The MmFeB compounds showed effects due to the cerium (lowering the Curie temperature) as well as due to the neodymium (spin reorientation at low temperatures). 相似文献
6.
Using different calorimeters, the following measurements have been carried out.
- 1.(i) The integral enthalpies of mixing of CeCu binary and some CeMgCu ternary liquid alloys,
- 2.(ii) The enthalpy of formation and the enthalpy of melting of the intermetallic compound CeCu2.
- 3.(iii) The heat content of solid and liquid CeCu2.
7.
《Journal of solid state chemistry》1987,69(1):186-188
ErBa2Cu3O7 and Er0.5Y0.5Ba2Cu3O7 are both high-Tc superconductors attaining zero resistance above 80 K. Preliminary studies indicate that Yb1−xYxBa2Cu3O7 also exhibits zero resistance above 77 K. 相似文献
8.
《Journal of the Less Common Metals》1991,167(2):373-379
Thermodynamic measurements by the electromotive force method were made on the binary intermetallic phases URu3 and U3Ru5 and on the ternary carbides URu3C0.7 and U2RuC2 of the URu and the URuC systems between 950 and 1200 K using galvanic cells with CaF2 single crystal electrolytes: U, UF3¦CaF2¦UF3, URu3, Ru; U, UF3¦CaF2¦UF3, U3Ru5, URu3; Ru, URu3, UF3¦CaF2¦UF3, URu3C0.7, Ru, C; U, UF3¦CaF2¦UF3, URu3C0.7, U2RuC2, C. The Gibbs energies of formation of URu3, U3Ru5, URu3C0.7 and U2RuC2 were evaluated from the measured electromotive force which give fΔGo〈URu3〉 = −199 100 + 35.9 T J mol−1fΔGo〈U3Ru5〉 = −398 600 + 43.6 T J mol−1fΔGo〈URu3C0.7〉 = −192 600 + 2.5 T J mol−1fΔGo〈U2RuC2〉 = −380 200 + 52.5 T J mol−1 The implications of these thermodynamic data for the behaviour of the fission product ruthenium in irradiated carbide fuels are discussed. 相似文献
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10.
《Journal of Inorganic and Nuclear Chemistry》1979,41(12):1787-1792
The liquid-liquid extraction model for a binary metal system successfully applied to the lanthanide nitrate system was found to be applicable to the binary metal-mixed ligand system only when equal mole fractions of each metal components are present in the feed solution. The agreement in this special case is explained satisfactorily in terms of the two-suffix Margules equations. The lack of agreement between the chemically based model and the experimental data was attributed to the effects of the stability constants and the degree of formation of the lanthanide mixed ligand complexes on the separation factors. 相似文献
11.
《Journal of solid state chemistry》1987,69(1):55-66
The AsGeTe system is formed by three independent triangles, corresponding to the two quasibinary systems GeAsGeTe and As2Te3GeTe. The presence of four phases As2GenTe3+n (n = 1 to 4) having peritectic decomposition introduces eight ternary peritectic invariants, whose temperatures and compositions are described. The three ternary eutectics have the following characters: E1, As19Ge52Te29 (662°C); E2, As42Ge5Te53 (368°C); E3, As22Ge5Te73 (350°C). 相似文献
12.
《Annales de Chimie Science des Materiaux》2002,27(3):99-109
The processing of metallic alloys through the procedure of equal-channel angular pressing (ECAP) provides an opportunity for achieving superplastic ductilities at very high strain rates. This paper reports experimental data from an investigation of a series of AlMgScZr alloys processed by ECAP. The results show the occurrence of high tensile ductilities at testing strain rates above 10−2 s−1. 相似文献
13.
《Annales de Chimie Science des Materiaux》2001,26(5):21-28
Transformation plasticity of a Fe18Mn8Cr5Ni5Si shape memory steel. This paper presents an experimental study of the transformation plasticity related to the γ→ε martensitic transformation in a Fe-18Mn-8Cr-5Ni-5Si shape memory steel. Under a weak bending stress the as-quenched austenitic samples showed a transformation plasticity by cooling at 170K with a plasticity coefficient h≈2. During heating, this transformation plasticity, related to the memory effect, is reversible, partially or completely, depending on whether the initial stress was maintained or removed at 295K during heating. 相似文献
14.
《Journal of solid state chemistry》1987,71(2):562-565
A hypothetical oxygen pressure-composition phase diagram and a projection of the oxygen pressure-temperature-composition diagram on the composition triangle were constructed from phase equilibria in the system MnCrO on the basis of the data available in literature. The temperature-composition phase equilibrium diagram of this same system in air was specified. Isomorphism of solid solutions with spinel and hausmannite structure and their intertransformation was studied. Two chemical compounds, MnCr2O4 and Cr4Mn28O48, are supposed to exist in the system. 相似文献
15.
The PtGaAs solid state equilibrium phase diagram was determined at 600 °C with the use of X-ray powder diffraction, electron probe microanalysis (EPMA) and scanning electron microscopy (SEM). No ternary PtGaAs phases were found and limited solid solubility was measured in the constituent binary PtGa and PtAs compounds. GaAs, PtGa and PtAs2 form a region of three-phase equilibrium which dominates the GaAs side of the phase diagram. The phase diagram is in agreement with previous observations that PtGa and PtAs2 are the stable phases when platinum thin films are reacted to completion on GaAs. 相似文献
16.
《Thermochimica Acta》1979,29(2):327-332
Sintering studies of WC-11%Co samples have been performed in a dilatometer. The temperature dependence of the shrinkage and the shrinkage rate during heating and isothermal treatment has been determined using computer evaluation. The relative magnitude of the densification in the solid and liquid states, respectively, has been determined and correlated to the CoWC phase diagram. Furthermore, some structural changes occurring under decarburizing conditions have been explained. Mechanisms for solid and liquid state sintering are presented. 相似文献
17.
《Fluid Phase Equilibria》1988,39(1):101-110
Bubble-point pressures of the H2COCO2 system were measured at temperatures from 253.15 to 303.15 K and pressures up to 9 MPa. Multiple bubble-points were observed within certain limits of hydrogen compositions. The data have been compared with the calculated results by the Redlich-Kwong and the Peng-Robinson equations of state. 相似文献
18.
《European Journal of Solid State and Inorganic Chemistry #》1998,35(8-9):591-594
It has been found experimentally that phase diagram for the system Bi2O3CaOSrOCuO in SrO-rich region at 850°C in the open air includes three elementary tetrahedra: CaOSrOSr6Bi2O11Sr2CuO3, CaOSr2CuO3Sr6Bi2O11Sr3,5Ca0,5Bi2O7 and Sr3Bi2O6Sr6Bi2O11Sr3,5Ca0,5Bi2O7 Sr2CuO3. In the considered interval of corresponding oxide concentrations quaternary oxides are not formed under the above conditions. 相似文献
19.
《Journal of Inorganic and Nuclear Chemistry》1981,43(6):1415-1417
PtCl42− with the ligand HS(CH2)3Cl affords a linear polymer which is converted into the hexamer title compound by heating in xylene in the presence of a small amount of dimethylsulphoxide. The hexamer undergoes Cl substitution upon reaction with NaBr or NaI. From the reaction of PtCl2 with the Grignard reagent of o-allyl-p-methyl-chlorobenzene is obtained the monomer complex Pt[C6H3(CH2CH CH2-o) (CH3p)]2. The biological properties of the complexes as inhibitors of DNA, RNA and protein synthesis has been evaluated. 相似文献
20.
《Solid State Sciences》2001,3(1-2):49-56
For application of LnSiON (Ln=Y, Gd and La) oxynitride materials, e.g. as host-lattices for lamp phosphors, oxidation resistance up to about 600 °C in air is a prerequisite. In this study we prepared LnSiON (Ln=Y, Gd and La) powders by solid state reaction and observed via TGA/DTA-experiments that most compounds are oxidation resistant up to 600 °C in air. The stability in air at high temperatures increases going from Ln5(SiO4)3N, Ln4Si2O7N2, LnSiO2N, Ln2Si3O3N4 to Ln3Si8O4N11. This is explained by an increasing cross-linking between the siliconoxygennitrogen tetrahedra in this sequence. For the lattices with less cross-linking between the siliconoxygennitrogen tetrahedra we observed that the oxidation resistance decreases slightly going from Y and Gd to La. For these lattices, also, an additional weight gain was observed during the oxidation reaction, which was higher than expected for complete oxidation. The additional weight gain was ascribed to an intermediate phase in which nitrogen retention takes place. 相似文献