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1.
Cu0.50Cr0.50PS3 is a new lamellar compound obtained from the elements at 700°C in evacuated silica tubes. The unit cell is monoclinic with a = 5.916 (1) Å; b = 10.246 (2) Å; c = 13.415 (5) Å; β = 107.09 (3)°. The structure is built up with S|Cu0.33Cr0.33(P2)0.33|S slabs in which copper, chromium, and (P2) pairs share the octahedral voids between two sulfur layers. Copper is not located at the center of its octahedral sites but is distributed among a continuous series of positions within these sites. This complex distribution has been simulated, attributing to copper two crystallographic eightfold positions with important thermal factors, especially perpendicular to the a-b plane. EPR studies and optical and magnetic measurements show that chromium is present as Cr3+ ions. The magnetic study suggests that, below TN ~ 30 K, this compound is a weakly anisotropic antiferromagnet consisting possibly of ferromagnetic layers which are antiferromagnetically coupled to adjacent layers. A good fit with the experimental results is obtained by means of calculations performed on the basis of a two-dimensional Heisenberg model.  相似文献   

2.
The phase diagram Cu2SeAs2Se3 was investigated by thermal and X-ray methods. Cu2Se has a limited solubility for As2Se3 (5 mole% at 769 K). The stoichiometric compound Cu3AsSe3 exists between 696 and 769 K. Cu4As2Se5, a phase at 66.6 mole% Cu2Se, decomposes peritectically at 746 K. The narrow homogeneity range (4 mole% at 683 K) extends far into the ternary space. CuAsSe2 also decomposes peritectically at 683 K. A degenerated eutectic between CuAsSe2 and As2Se3 was found at 641 K. Single crystals of Cu4As2Se5 were grown in a salt melt. A metastable modification of the high-temperature phase Cu3AsSe3 can be obtained by quenching. Cu4As2Se5 (space group R3, lattice constants a = 1404.0(1) pm, c = 960.2(1) pm), Cu6As4Se9, obtained by Cambi and Elli, and Cu7As6Se13 of Takeuchi and Horiuchi are different versions of a sphalerite-type compound with a broad homogeneity range in the system CuAsSe. CuAsSe2 is possibly monoclinic with lattice parameters of a = 946.5(1) pm, b = 1229.3(1) pm, c = 511.7(1) pm, and β = 98.546(4)°. The enthalpy of mixing of Cu2Se and As2Se3 in the liquid state is endothermic.  相似文献   

3.
Upon being brought into contact with each other, α-Cu2Se and α-CuSe pellets reacted entirely forming Cu3Se2 at room temperature. After 10 days, the reaction was almost completed. Weight measurements revealed that copper atoms migrated from α-Cu2Se to α-CuSe. Solid-state reactions were also observed in the (α-Cu2Se+Cu3Se2) and (α-Cu2Se+CuS) systems, but not in the (Cu3Se2+α-CuSe), (Cu2S+CuS) and (α-CuSe+Cu2S) systems. Therefore, the high ionic conductivity of copper ions in α- and β-Cu2Se is considered to be responsible for the solid-state reactions observed in these systems.  相似文献   

4.
In order to understand the structural transformations leading to high ionic conductivity of Cu+ ions in Cu6PS5I argyrodite compound, the detailed structure analysis based on single-crystal X-ray diffraction has been performed. Below the phase transition at Cu6PS5I belongs to monoclinic, ferroelastic phase (space group Cc) with ordered copper sublattice. Above Tc delocalization of copper ions begins and crystal changes the symmetry to cubic superstructure with space group F-43c (, z=32). Finally, above increasing disordering of the Cu+ ions heightens the symmetry to F-43m (, z=4). In this work, the final structural model of two cubic phases is presented including the detailed temperature evolution of positions and site occupation factors of copper ions (R1=0.0397 for F-43c phase, and 0.0245 for F-43m phase). Possible diffusion paths for the copper ions are represented by means of the atomic displacement factors and split model. The structural results coincide well with the previously reported non-Arrhenius behavior of conductivity and indicate significant change in conduction mechanism.  相似文献   

5.
Phase equilibria in the system CuCu2OTiO2 were investigated in the temperature range of 1160–1270 K by means of thermogravimetry and measurements of the oxygen partial pressure. The tie lines on the isothermal phase diagram run from the phase Cu3TiO4 to CuO, Cu2O, and TiO2. The existence of Cu3TiO5 and Cu2TiO3 could not be confirmed in this temperature range. The phase “Cu3TiO4” is only stable above about 1140 K and its composition fluctuates between about Cu3TiO4.3 and Cu3TiO3.9. The formation of Cu3TiO4.3 according to the reaction 1.6 CuO + 0.7 Cu2O + TiO2 = Cu3TiO4.3 is endothermic: (1160 < T < 1270 K) ΔH° = (7600 ± 450 J-mole?1; ΔS° = (6.7 ± 0.4) J·K?1·mole?1. The standard Gibbs free energy, enthalpy, and entropy of formation of Cu3TiO4.3 at 1200 K are ΔG°f = ?101.39 kJ, ΔH°f = ?1115.84 kJ, and S°f = 466.76 J·K?1. Rather similar values were found for Cu3TiO3.9.  相似文献   

6.
以醋酸铜/硝酸铜和硼酸为原料,柠檬酸作发泡剂,采用溶胶-凝胶法制得了高纯度的单晶结构硼酸铜(Cu3B2O6/CuB2O4). 利用X射线衍射(XRD)、扫描电镜(SEM)、高分辨率透射电镜(HRTEM)、热重-差热分析(TGDTA)等对样品进行了表征,并考察了Cu3B2O6/CuB2O4在可见光(400 nm<λ<1100 nm)下对亚甲基蓝(MB)溶液的催化降解性能. 结果表明,两种结构的硼酸铜都具有良好的光催化性能. 当亚甲基蓝的初始浓度为50 mg·L-1,催化剂用量为1 g·L-1,光照6 h后,CuB2O4对亚甲基蓝的光催化降解率为63.36%,Cu3B2O6对亚甲基蓝的光催化降解率为99.52%. 紫外-可见漫反射光谱(UV-Vis DRS)结果表明,Cu3B2O6的中间能态宽度为1.78 eV,小于CuB2O4的中间能态宽度(1.95 eV),且Cu3B2O6的禁带宽度较窄(Eg=2.34 eV),不仅可以发生价带顶与中间能态的电子跃迁,同时可以发生禁带间的电子跃迁,所以Cu3B2O6比CuB2O4具有更高的可见光催化性能.  相似文献   

7.
The crystal structures of the Rh[(EtO)2PS2]3 (I) and Co[(PhO)2PS2]3 (II) chelate compounds were determined from X-ray diffraction (XRD) data (CAD-4 diffractometer, MoK β radiation, 1193 F hkl , R = 0.0516 for I and 513 F hkl , R = 0.0305 for II). Crystals I are monoclinic: a = 14.233(3) Å, b = 13.570(3) Å, c = 14.272(3) Å; β = 90.66(3)°, V = 2756.3(10) Å3, Z = 4, ρcalc = 1.587 g/cm3, space group C2/c. Crystals II are trigonal: a = 15.149(2) Å, c = 30.306(6) Å; V = 6023.2(16) Å3, Z = 6, ρcalc = 1.493 g/cm3, space group R3ˉ. Structures I and II consist of discrete mononuclear molecules. The coordination polyhedra of the M atoms (M = Rh, Co) are distorted octahedra formed by six sulfur atoms of three cyclic bidentate (RO)2 PS2 ligands. Original Russian Text Copyright ? 2008 by R. F. Klevtsova, L. A. Glinskaya, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 2, pp. 330–334, March–April, 2008.  相似文献   

8.
Two copper tantalates, Cu5Ta11O30 (1) and Cu3Ta7O19 (2), were synthesized by solid-state and flux synthetic methods, respectively. A synthetic route yielding 2 in high purity was found using a CuCl flux at 800oC and its structure was characterized using powder X-ray diffraction (XRD) data (P63/m (no. 176), Z=2, a=6.2278(1) Å, and c=20.1467(3) Å). The solid-state synthesis of 1 was performed using excess Cu2O that helped to facilitate the growth of single crystals and their characterization by XRD (P6¯2c (no. 190), Z=2, a=6.2252(1) Å, and c=32.516(1) Å). The atomic structures of both copper tantalates consist of alternating single and double layers of TaO7 pentagonal bipyramids that are bridged by a single layer of isolated TaO6 octahedra and linearly-coordinated Cu+. Measured optical bandgap sizes of ∼2.59 and ∼2.47 eV for 1 and 2 were located well within visible-light energies and were consistent with their orange-yellow colours. Each also exhibits optical absorption coefficients at the band edge of ∼700 and ∼275 cm−1, respectively, and which were significantly smaller than that for NaTaO3 of ∼1450 cm−1. Results of LMTO calculations indicate that their visible-light absorption is attributable mainly to indirect bandgap transitions between Cu 3d10 and Ta 5d0 orbitals within the TaO7 pentagonal bipyramids.  相似文献   

9.
将过渡金属配合物阳离子([M(DETA)2]n+(M=Cu2+,Ni2+,Co3+;DETA=Diethylenetriamine,二乙烯三胺)作为客体插入层状MnPS3层间得到了相应的3个夹层化合物。通过X-射线粉末衍射、元素分析和红外光谱对夹层化合物的结构进行了表征。结果表明,与主体MnPS3 0.65 nm的层间距相比较,夹层化合物(Mn0.88PS3[Cu(DETA)2]0.12)的层间距扩大了0.32 nm,由此推测客体[Cu(DETA)2]2+在层间以平面四方的配位形式存在,而另2个夹层化合物(Mn0.79PS3[Ni(DETA)2]0.21和Mn0.74PS3[Co(DETA)2]0.17)的层间距扩大了0.48 nm,说明客体[(M(DETA)2]n+,M=Co3+,Ni2+) 在主体层间以八面体配位形式存在。磁性测试结果表明过渡金属离子[(M(DETA)2]n+(M=Cu2+,Co3+)的插入能引起主体MnPS3的磁性在35~40 K发生由顺磁向亚铁磁性的转变并表现自发磁化,而客体[Ni(DETA)2]2+却使夹层化合物的反铁磁相互作用增强,抑制了自发磁化的发生。  相似文献   

10.
Crystal structures of chelate compounds Ni[(iso-C4H9)2PS2]2 (I) and Pd[(iso-C4H9)2PS2]2 (II) have been determined by X-ray diffraction: diffractometer X8-APEX, MoK α∔ -radiation, 1048 F hkl , R = 0.0544 for I and CAD-4 diffractometer, MoK α∔ -radiation, 1283 F hkl , R = 0.0347 for II. The crystals are rhombic: a = 12.921(5) Å, b = 17.094(5) Å, c = 22.971(5) Å; V = 5074(3) Å3, Z = 8, calc = 1.250 g/cm3, space group Pbca for I and a = 13.312(3) Å, b = 16.130(7) Å, c = 23.171(5) Å; V = 4975(3) Å3, Z = 8, ρcalc = 1. 208 g/cm3, space group Pbca for II. The structures of I and II are formed by discrete mononuclear molecules. Coordination cores MS4 (M = Ni, Pd) approach planar square configurations. Original Russian Text Copyright ? 2005 by L. A. Glinskaya, T. G. Leonova, T. E. Kokina, R. F. Klevtsova, and S. V. Larionov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 4, pp. 715–720, July–August, 2005.  相似文献   

11.
Five chemical compounds, CuMoO4, Cu3Mo2O9, Cu2Mo3O10, Cu6Mo4O15, and Cu4?x Mo3O12 (0.10 ? x ? 0.40), were identified in the system Cu2OCuOMoO3 and characterized by DTA, X-ray powder patterns, ir spectra, and magnetic properties. Cupric molybdates CuMoO4 and Cu3Mo2O9 are stable in air up to 820 and 855°C, respectively, melting at these temperatures with simultaneous decomposition (oxygen loss). Congruent mp of cuprous molybdates Cu2Mo3O10 and Cu6Mo4O15, in argon, are 532 and 466°C, respectively. Nonstoichiometric phase Cu4?x Mo3O12 = Cu2+3Cu01?xMo6+3O12, melts in argon between 630 and 650°C depending on the value of x and at 525–530°C undergoes polymorphic transformation. Areas of coexistence of the above-mentioned phases are determined. The μeff of Cu2+ ions and θ values are: 1.80 B.M. and 28°K for CuMoO4, 1.71 B.M. and ? 12°K for Cu3Mo2O9, and 1.74 B.M. and ? 93°K for Cu4?xMo3O12. Below 200°K CuMoO4 becomes antiferromagnetic. Cu2Mo3O10 and Cu6Mo4O15 show weak temperature-independent paramagnetism.  相似文献   

12.
The electronic and physical properties of Cu2.33V4O11 were characterized by electrical resistivity, magnetic susceptibility and X-ray photoelectron spectroscopy (XPS) measurements and by tight-binding electronic band structure calculations. Attempts to prepare Cu2.33−xV4O11 outside its narrow homogeneity range led to a mixture of Cu2.33V4O11, CuVO3 and β-CuxV2O5. The magnetic susceptibility data show no evidence for a magnetic/structural transition around 300 K. The XPS spectra of Cu2.33V4O11 reveal the presence of mixed valence in both Cu and V. The [Cu+]/[Cu2+] ratio is estimated to be 1.11 from the Cu 2p3/2 peak areas, so [V4+]/[V5+]=0.56 by the charge balance. Our electronic structure calculations suggest that the oxidation state of the Cu ions is +2 in the channels of CuO4 tetrahedra, and +1 in the channels of linear CuO2 and trigonal planar CuO3 units. This predicts that [Cu+]/[Cu2+]=1.33 and [V4+]/[V5+]=0.50, in good agreement with those deduced from the XPS study.  相似文献   

13.
朱珠  罗贸兰  张杰  杨琴  周丽梅 《分子催化》2017,31(5):455-462
我们通过原位还原的方法将吸附在g-C3N4表面上Cu2+还原,制备出Cu2O/g-C3N4复合材料,并利用XRD、SEM、FT-IR、XPS等分析手段表征Cu2O/g-C3N4.表征结果显示:Cu元素主要以Cu2O的形式吸附在g-C3N4载体上.另外,还考察了Cu2O/g-C3 N4在“一锅法”合成吲哚-2-甲酸乙酯的反应中的催化性能.结果表明:即使在较低的催化担载量和温和的反应条件下,Cu2O/g-C3 N4仍能表现出良好的催化性能并获得44.1%的收率.  相似文献   

14.
CuSbTeO3Cl2 has been isolated during an investigation of the system Cu2O:TeCl4:Sb2O3:TeO2. The new compound is light yellow and crystallises in the monoclinic system, space group C2/m, a=20.333(5) Å, b=4.0667(9) Å, c=10.778(2) Å, Z=6. The structure is layered and is built up from corner and edge sharing [(Sb,Te)O4E] trigonal bipyramids that have the lone pair (E) directed towards one of the equatorial positions, those groups build up [(Sb,Te)2O3E2+]n layers. The copper and the chlorine atoms are located in between those layers. There are two different Cu positions. The [Cu1Cl4] group is a slightly distorted tetrahedron and these tetrahedra make up chains by corner sharing. The electron density for the half occupied Cu2 atom is spread out in the structure like a worm that run along the b-axis in the space in between two chains of [Cu1Cl4] tetrahedrons. Analysis of the diamagnetic response in magnetic susceptibility measurements is in perfect agreement with a Cu+ valence. Conductivity measurements in the temperature range 355–590 K gives an activation energy of 0.55 eV. The delocalised Cu2 position in the structure suggests that the compound is a Cu+ ionic conductor along the b-axis.  相似文献   

15.
Mixed-ligand complexes [Ni(4-NH2Py) (i-Bu2PS2)2] (I) and Ni(4-NH2Py)2(i-Bu2PS2)2 (II) have been synthesized. Single crystals were grown and X-ray diffraction data (CAD-4 diffractometer, MoK α radiation, 1477 F hkl , R = 0.0320) were used to determine the structure of I. The crystals are orthorhombic: a = 10.675(1) Å; b = 21.681(2) Å; c = 26.302(4) Å, V = 6087.5(12) Å3, Z = 8, ρ(calc) = 1.247 g/cm3, space group Pbca. Complex I possesses a mononuclear molecular structure. The coordination polyhedron of the Ni atom is a tetragonal pyramid NS4 whose base is formed by four S atoms of two cyclic bidentate ligands i-Bu2PS 2 and the axial position is occupied by the N atom of the 4-NH2Py cycle. According to electron spectroscopy data, complex II has an octahedral N2S4 environment of the Ni atom.Original Russian Text Copyright © 2004 by T. E. Kokina, L. A. Glinskaya, E. A. Novoselova, R. F. Klevtsova, and S. V. Larionov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 5, pp. 899–904, September–October, 2004.  相似文献   

16.
The interaction of the Co(iso-Bu2PS2)2 chelate with 4-NH2Py afforded a paramagnetic complex [Co(4-NH2Py)(iso-Bu2PS2)2] (μeff = 4.53 BM). Single crystals of [Ni(4-NH2Py)2(iso-Bu2PS2)2] (I) and [Co(4-NH2Py)(iso-Bu2PS2)2] (II) were grown and used for X-ray diffraction investigation (X8 APEX diffractometer, MoK α radiation). Crystals I are monoclinic with unit cell parameters a = 12.5336(5) Å, b = 9.4356(4) Å, c = 16.4095(6) Å; β = 111.351(1)°; V = 1807.4(1) Å3; Z = 2, ρ = 1.223 g/cm3, space group P21/n. Crystals II are triclinic with unit cell parameters a = 8.7572(4) Å, b = 9.6934(6) Å, c = 18.665(1) Å; α = 79.374(2)°, β = 87.049(2)°, γ = 75.640(2)°; V = 1508.6(1) Å3; Z = 2, ρ = 1.259 g/cm3; space group . The structures of I and II are formed by isolated mononuclear molecules. The coordination unit is NiN2S4 (octahedron) in I and CoNS4 (tetragonal pyramid) in II. The 4-NH2Py molecule is coordinated through the N atom of the heterocycle. Electronic spectroscopy data for II agree with the symmetry of the NS4 polyhedron found by X-ray diffraction (XRD) analysis. The noncoordinated amine groups link the complex molecules via N-H...S hydrogen bonds. __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 46, No. 6, pp.1072–1080, November–December, 2005. Original Russian Text Copyright ? 2005 by T. E. Kokina, L. A. Glinskaya, E. A. Sankova, R. F. Klevtsova, and S. V. Larionov  相似文献   

17.
ESR spectra obtained from γ-irradiated triphenylphosphine sulphide in CD3OD are shown to be in agreement with novel tetrahedral phosphoranyl radicals (Ph3·PS? and Ph3·PSR).  相似文献   

18.
The heteroligand complex Nd(Phen){(iso-C4H9)2PS2}2(NO3) (I) was synthesized and its IR spectrum was analyzed. The anions (iso-C4H9)2PS2/− and N3/− act as bidentate cyclic ligands. The single crystals of [Nd(Phen){iso-C4H9)2PS2}3] (II) were obtained on evaporation of a solution of complex I in a mixture CH2Cl2-hexane and were studied by X-ray diffraction. Crystals II are triclinic: a = 10.5509(5); b = 14.7432(8), c = 16.8503(10) ?; α = 102.882(2)°, β = 97.211(2)°, γ= 108.087(2)°, V = 2374(2) ?3, Z = 2, ρ(calcd.) = 1.332 g/cm3, space group . The coordination polyhedron of the Nd atom in a separate mononuclear molecule II is a distorted dodecahedron N2S6. The molecules are bound by weak van der Waals and π-π interactions. The photoluminescence spectra of complexes I, II were measured and interpreted. Original Russian Text ? S.V. Larionov, V.L. Varand, R.F. Klevtsova, T.G. Leonova, L.A. Glinskaya, E.M. Uskov, 2008, published in Koordinatsionnaya Khimiya, 2008, Vol. 34, No. 12, pp. 944–950.  相似文献   

19.
Results of electrical conductivity measurements, thermal analysis, and X-ray diffraction studies indicate the existence of four phases, between 295 K and the melting points, in the system (Cs1?yRby)Cu4Cl3I2. These phases are designated α, á β, γ in order of decreasing temperature. The α phase is isostructural with α-RbAg4I5; the á phase is also cubic and very likely belongs to space groupP213, a subgroup ofP4132 andP4332 to which the α phase belongs. There is a high probability that the á → α transition is continuous. The á → α transition is not discernible in the conductivity measurements or thermal analysis; therefore the line of á-α transitions is presently unknown. The β phase transforms to the á and the γ phase transforms to the β phase wheny ≤ 0.36; the γ phase transforms to the α phase wheny ≥ 0.36. That is, there is a triple point aty = 0.36, T = 399K. The γ-β, β-α′, and γ-α transitions are all hysteretic and are therefore first order. The conductivities of the β phases are relatively low and the enthalpies of activation relatively high. The conductivity of the β phase decreases with increasingy. The β phase probably belongs to space groupR3, in which the Cu+ ions can be ordered. The α and á phases are the true solid electrolytes; the conductivities are high, >0.73 Ω?1cm?1 at 419 K, and the enthalpies of activation of motion of the Cu+ ions low, 0.11 eV.In the system CsCu4Cl3(I2?xClx), 0 ≤ x ≤ 0.25, the Cl? for I? substitutions affect the transitions to only a small extent relative to the stoichiometric compound. The β phase occurs for allx and transforms to á.  相似文献   

20.
Semiconducting copper sulphide (Cu2S) thin films have been deposited on various substrates (SnO2:F/glass, glass) by the simple and economical chemical bath deposition technique. The depositions were carried out during a deposition time of about 32.5 min in the pH range of 9.4 to 11. The synthesized Cu2S thin films were characterized using various techniques without any annealing treatment. X-ray diffraction study shows that Cu2S films exhibit the best crystallinity for pH = 10.2. For this pH value, Auger electron spectroscopy investigations show that Cu2S thin films grown on an SnO2/glass substrate exhibit stochiometric composition with [Cu]/[S] concentrations ratio equal to 2.02. Using the Kelvin method, the work function difference (ФmaterialФprobe) for the Cu2S films deposited on SnO2/glass substrates at the optimum pH value was found to be equal to 145 meV. Hall measurements confirm the p-type electrical conductivity of the obtained films. The electrical resistivity was of the order of 3.85 × 10−4 Ω-cm. The transmission and reflection coefficients vary in the range of [35–60] % and [5–15] % respectively, in the visible range, and the band gap energy is about 2.37 eV.  相似文献   

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