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1.
T-x diagram of the γLa2S3 γNd2S3 system was plotted for the temperature interval 1400–2100°C. γLa2S3 and γNd2S3 form unlimited solid solutions of the substitution type. Basing on this phase diagram the theoretical distribution curves of Nd2S3 along the ingot of length were calculated. The experimental distribution curves were determined by chemical and electron microprobe measurements of La and Nd content in γ(La,Nd)2S3 ingots directionally solidified from the melt of different composition. Character of the component distribution in the ingots shows that diffusion of neodymium and lanthanum is exeptionally fast at 1700–2000°C. This phenomenon is explained by vacancy diffusion mechanism in γLa2S3 γNd2S3 solid solutions. Crystal structure of these solid solutions belongs to Th3P4 type with high concentration of randomly distributed cation vacancies. 相似文献
2.
The Preparation of the binary sulphides CaS, La2S3, Er2S3, and Sm2S3 in high purity powder form from the elements is described, with the subsequent synthesis of ternary sulphides with Th3P4 and spinel structures. Single crystals of CaLa2S4 and CaLa2S4La2S3 solid solutions, up to 10 mm3 volume, have been grown from the melt in sealed crucibles using the Stöber technique. 相似文献
3.
Yu. I. Shtern A. S. Malkova A. S. Pashinkin V. A. Fedorov 《Inorganic Materials》2008,44(10):1057-1059
The heat capacity of the n-Bi2Te2.88Se0.12 and p-Bi0.52Sb1.48Te3 solid solutions has been measured from 360 to 600 K. The data, represented in the form C
p
= a + bT + cT
−2, have been used to evaluate the thermodynamic functions of the solid solutions in the range 298.15 to 600 K.
Original Russian Text ? Yu.I. Shtern, A.s. Malkova, A.S. Pashinkin, V.A. Fedorov, 2008, published in Neorganicheskie Materialy,
2008, Vol. 44, No. 10, pp. 1184–1186. 相似文献
4.
The isotypic compounds BaGa2S4 and BaAl2S4 crystallize in the cubic system, space group Pa3 with the constants: BaGa2S4: a = 1268.5±0.4 pm, BaAl2S4: a = 1265.0±0.7 pm. BaS4- resp. AlS4-tetrahedra are connected by common corners to a threedimensional net. The Ba-ions are located in holes with coordination numbers 6 resp. 12. 相似文献
5.
The crystal structures of the new compounds Na2Cu4S3 and KCu3Te2 have been solved. Na2Cu4S3 crystallizes in the K2Ag4S3 structure (space group: C2/m, a = 1563(3) pm, b = 386(2) pm, c = 1033(2) pm, β = 107.6o, N = 4), KCu3Te2 in the CsAg3S2 structure (space group: C2/m, a = 1645.3(9) pm, b = 429.4(4) pm, c = 866.1(6) pm, β = 111.86o, N = 4). 相似文献
6.
The crystal structures of FeSc2S4 and Fe0.85Sc2.10S4 have been determined by three dimensional X-ray diffraction. The cubic cells, space group Fd3m, have lattice constants for FeSc2S4 and for Fe0.85Sc2.10S4. Iron is divalent and scandium trivalent. FeSc2S4 is a direct spinel structure, Fe0.85Sc2.10S4 is near a spinel structure. Only 0,5 iron atom is on every 8a position; 0,175 Fe and 1,05 Sc lie on octahedral 16d and 16c site. 相似文献
7.
K. Yasuda 《Materials Research Bulletin》2010,45(9):1278-11034
Pt/CeO2-ZrO2-Bi2O3 catalysts for catalytic combustion of acetaldehyde, which is one of volatile organic compounds (VOCs), were prepared by a wet impregnation method in the presence of polyvinylpyrrolidone K25 (PVP). The addition of PVP in the preparation process was effective to enhance the specific surface area and the Pt2+ ratio on the surface. Additionally, the pore volume and size of the catalysts were modified by the PVP addition. The Pt/CeO2-ZrO2-Bi2O3 catalysts are specific for the total acetaldehyde oxidation and CO and any acetaldehyde-derivative compounds were not observed as by-products. The catalytic activity of the Pt/CeO2-ZrO2-Bi2O3 catalysts was significantly promoted by the PVP addition and the total oxidation temperature decreased. By the optimization of the amount of platinum, the complete oxidation of acetaldehyde was realized at a temperature as low as 140 °C on a 10 wt%Pt/CeO2-ZrO2-Bi2O3 catalyst. 相似文献
8.
The crystal structure of MnSc2S4 (, space group Fd3m) and Mn2.29Sc1.14S4 (, space groupe Fd3m) were determined by three dimensional X-Ray diffraction. MnSc2S4 is a normal spinel structure and the atomic distribution shows that Mn2.29Sc1.14S4 structure is intermediate between the rocksalt (MnS) and the spinel (MnSc2S4) types. Similar behaviour of Mn and Fe atoms in MnSSc2S3 and FeSSc2S3 systems was observed. 相似文献
9.
Lei YingChanggui Lin Yinsheng XuQiuhua Nie Feifei ChenShixun Dai 《Optical Materials》2011,33(11):1775-1780
Novel chalcogenide glasses based on GeS2-In2S3-Sb2S3 system were prepared by conventional melt-quenching method and their physicochemical properties, e.g. glass transition temperature, density, and Vickers micro-hardness, were studied in detail. The results show that the thermal, mechanical, and optical properties depend largely on four-coordinated Ge or In entities and are sensitive to the variation of the connectivity in the GeS2-In2S3-Sb2S3 glass network. It is a promising chalcogenide glass system suitable for rare earth doping or crystallization of rare earth doped crystals, which aims at optical applications of IR optical amplifier or efficient solid state laser. 相似文献
10.
The ferrimagnetic spinels CoCr2S4 (TC ≈ 220 K) and FeCr2S4 (TC ≈ 180 K) were found to form a complete series of solid solutions. The mixed compounds are semiconductors with Curie temperatures varying almost linearly with the composition. The iron is concluded to be divalent in the whole composition range. All samples exept CoCr2S4 are p-conducting, with negative magnetoresistance values close to that of p-FeCr2S4.The possibilities to incorporate trivalent iron into CoCr2S4 are discussed. 相似文献
11.
Marìe-Paule Pardo Leïla Dogguy-Smiri Jean Flahaut Nguyen Huy Dung 《Materials Research Bulletin》1981,16(11):1375-1384
The system was studied by DTA, X-ray diffraction and in particular by the Guinier-Lenné method. Eight intermediate phases are described. 1) Three solid solutions in the Ga2S3 region : a) a wurtzite-type solid solution (T > 1000° C ; 0.05 < n < 0.23) (n = Fe at+Ga at), b) a blende-type solid solution (700°C < T < 980°C ; 0.10 < n < 0.20) with many stacking faults, c) a non-stoichiometric hexagonal phase α'Ga2S3 type (T < 700°C, 0.07 < n < 0.12). 2) for n = 0.20 and T = 540°C a superstructure of orthorhombic wurtzite-like array FeGa4S7. 3) From n = 0.20 through n = 0.27, a non stoichiometric superstructure of tetragonal-like array has the CdGa2S4 type (600°C < T < 1030°C). 4) For n = 0.33, the FeGa2S4 has two forms depending from the temperature : a) a low temperature form is trigonal ; b) a high temperature form is orthorhombic type ZnAl2S4. Transition temperature is 1010°C. 5) For n = 0.50, Fe2Ga2S5 polytypes : a) Fe2Ga2S5α 1T type Mn2Ga2S5 ; b) Fe2Ga2S5 2H ; c) Fe2Ga2S5 3R type Mn2Al2Se5. A phase diagram is proposed. 相似文献
12.
Mo3S4 and Mo3Se4 were found to undergo topotactic electron-ion exchange reactions at ambient temperatures in aqueous and non-aqueous electrolytes containing transition or main group cations. The products of cathodic reduction are ternary phases AxMo3X4. Mobilities of the exchangeable cations are rather high inside the solid and are responsible for high reaction rates. Cathodic reduction of Mo3S4 and Mo3Se4 represents a suitable method for the preparation of both stoichiometric and nonstoichiometric ternary phases which are of interest with respect to the superconducting properties of these chalcogenides. 相似文献
13.
Marko Hrovat Andreja Ben?an Janez Holc Tadej Rojac Marija Kosec 《Materials Research Bulletin》2011,46(1):98-100
Subsolidus equilibria in air in the RuO2-Bi2O3-ZrO2 system were studied with the aim of obtaining information on possible interactions between a Bi2Ru2O7-based cathode and a ZrO2-based solid electrolyte in solid-oxide fuel cells (SOFCs). No ternary compound was found in the system. The tie lines are between Bi2Ru2O7 and ZrO2, and between Bi2Ru2O7 and gamma-Bi2O3—the ZrO2 stabilised Bi2O3 phase, stable at temperatures over 710 °C. 相似文献
14.
Peanut-shaped Sb2S3 superstructures have been synthesized via a hydrothermal process at 120 °C for 8 h using hydrochloric acid and antimony O-benzyl dithiocarbonate (benzylxanthate, Sb(S2COC7H7)3) as starting materials. The powder X-ray diffraction (XRD) pattern shows the product corresponds to the pure orthorhombic phase of Sb2S3, the purity and composition of which are further confirmed by X-ray photoelectron spectroscopy (XPS). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) studies reveal that the peanut-shaped Sb2S3 superstructures are aggregated by nanorods. The possible mechanistic pathways in the formation of the structures are discussed. 相似文献
15.
The system PbS-In2S3 was examined by differential thermal analysis (DTA), chemical vapour transport (CVT), and X-ray diffraction. Five new phases of compositions closely related to the 1:1 ratio were found and prepared as needle-shaped single-crystals; their crystal data are reported. The structures of PbIn2S4 (orthorhombic, Pnma, a=11.688(1), b=3.8528(1), , Z=4) and Pb6In10S21 (monoclinic, C2/m, a=27.629(3), b=3.8630(5), , β=95.9°, Z=2 were solved from 808 resp. 3554 independent reflexions and refined to R=0.116 resp. 0.068. In both structures the In-S coordination polyhedra are distorted octahedra, the Pb-S polyhedra are distorted bicapped trigonal prisms. 相似文献
16.
ZnIn2S4 thin films prepared by flash evaporation are polycrystalline and exhibit the structure of ZnIn2S4 on X-ray analysis. The films are photoconducting with a dark resistivity of about 103 ω cm. At low temperatures, when illuminated by gap energy light and subsequently measured in the dark, the films exhibit a residual conductivity which can be removed by heating the samples to room temperature. 相似文献
17.
18.
MgAl2S4 crystallizes in the orthorhombic system, space group Pnma (No 62) with the lattice constants: a=1251.1 ± 0.6 pm, b =722.0 ± 0.4 pm, c=592.1 ± 0.4 pm The compound is isotypic to BeAl2O4.Mg0.830In2.113S4 forms the spinel structure, space group Fd3m (No 227) with a=1071.9 ± 0.6 pm. 相似文献
19.
The phase diagrams of the chromium sulfide systems Cr1?xMxCr2S4, Cr1?xFexCr2S4, andCr1?xCoxCr2S4 were studied with the help of X-ray powder Guinier photographs of quenched samples. The phase widths of the monoclinic Fe3Se4 (Cr3S4) type solid solutions increase with increasing temperature from x < 0.1 below 500°C to x = 0.23, 0.45, and 0.44 for M = Mn, Fe, and Co, respectively, at 900°C. The observed alterations of the unit cell parameters, e.g. increase of the volume V, but decrease of the lattice constant a with increasing × for M = Mn and Fe, are discussed in terms of the ionic radii and metal-semiconductor transitions. The phase widths of the spinel type chromium sulfides MCr2S4 are very small for all temperatures studied. The relative stability of the Cr3S4 and the spinel structure can be interpreted using site preference and covalent bonding arguments. 相似文献
20.
Four intermediate phases are present ; PbGa2S4,orthorombic EuGa2S4-type (a = 20,44 ; b = 20,64 ; ) ; Pb2Ga2S5, orthorombic space group Pbca (a = 12,38 ; b = 11,90 ; ) ; and two Ga2S3-rich solid solutions, one of the wurtzite type at temperatures above 1000°C, one of the distorded blende type below about 970°C. PbGa2S4 has a peritectic decomposition at 930°C, and Pb2Ga2S5 at 900 ± 5°C. The eutectic is at 730°C for about n = 0,80 ( atomic). A glassy region is obtained by quenching the liquid phase and its extent depends on the quenching temperature (at 1000°C, between n = 0,25 and n = 0,50). 相似文献