The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the iso...The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the isothermal sections of the ternary system at 1673 K and 1873 K is well reproduced. According to the assessed isothermal section at 1723 K, no alumina dissolves into the tetragonal zirconia phase. Specimens with different alumina content are fabricated from commercial 12 mol pct CeO2-stabilized ZrO2 powder (12Ce-ZrO2). The thermodynamic properties are consistent with the observed microstructure, which present a combination of tetragonal phase and alumina grains.展开更多
A microporous organically-templated tungsten heteropolyacid, (C2N2H10)2 [H2P2W18O62]?8H2O, with a new type was hydrothermally synthesized by using ethylenediamine as the structure-directing agent. Its structure was ...A microporous organically-templated tungsten heteropolyacid, (C2N2H10)2 [H2P2W18O62]?8H2O, with a new type was hydrothermally synthesized by using ethylenediamine as the structure-directing agent. Its structure was determined by single-crystal X-ray diffraction analysis. Crystal data: monoclinic, space group P21/c, a = 14.633(4), b = 19.432(5), c = 26.776(5) ?, β = 117.849(11)o, V = 6732(3) ?3, Z = 4, Mr = 4615.48, Dc = 4.554 g/cm3, μ(MoKα) = 30.781 mm-1, F(000) = 7976, the final R = 0.0678 and wR = 0.1359. The crystal of the title compound is constructed by Dawson anions and organic dications forming a novel “hollow” channel system.展开更多
The title new compounds with chemical formula RNixBi2 were synthesized by arc melting method followed by annealing. The crystal structures refined by using Rietveld method and X-ray powder diffraction data are isotypi...The title new compounds with chemical formula RNixBi2 were synthesized by arc melting method followed by annealing. The crystal structures refined by using Rietveld method and X-ray powder diffraction data are isotypic to CaMnBi2 structure type, space group P4/nmm with a = 0.448350(4), c = 0.930026(2) nm, V = 0.186952(7) nm3 for YNi0.82Bi2, a = 0.448882(5), c = 0.93658(2) nm, V = 0.188715(8) nm3 for GdNi0.86Bi2, a = 0.448486(3), c = 0.93062(2) nm, V = 0.187185(6) nm3 for TbNi0.78Bi2 and a = 0.447493(4) nm, c = 0.925852(1) nm, V = 0.185402(6) nm3 for DyNi0.77Bi2, showing lanthanide contraction. The structure is characterized by layers of edge-sharing NiBi4 tetrahedron and covalently bonded Bi square net separated by rare earth atoms.展开更多
A novel metal organic compound of Zn2+ coordinated with 4,5-diazafluorene- 9-one-N2 (C22H12N6) has been synthesized under solvothermal condition. Single-crystal X-ray diffraction analysis showed that the compound is a...A novel metal organic compound of Zn2+ coordinated with 4,5-diazafluorene- 9-one-N2 (C22H12N6) has been synthesized under solvothermal condition. Single-crystal X-ray diffraction analysis showed that the compound is a one-dimensional zig-zag chain structure combined by Cl…H–C bonds. The crystal is of orthorhombic, space group Pnna, C22H12N6Cl2Zn, Mr = 496.65, a = 8.1132(13), b = 18.983(3), c = 13.116(2) ?, Z = 4, V = 2020.2(5) ?3, Dc = 1.633 g/cm3, μ = 1.504 mm-1, F(000) = 1000, T = 293(2) K, the final R = 0.0626 and wR = 0.1474 for 2390 unique reflections and 150 parameters with I > 2σ(I). The refinement method was full-matrix least-squares on F2 with GOF = 0.951. This compound was also characterized by FT-IR, Raman, UV-vis spectra, and TG-DTA.展开更多
The piezoresponse behavior dependence of the Pb(Mg1/3Nb2/3)O3-30%PbTiO3 single crystal on the vacuum degree has been investigated by scanning force microscopy in the piezoresponse mode under high vacuum. Unusual piezo...The piezoresponse behavior dependence of the Pb(Mg1/3Nb2/3)O3-30%PbTiO3 single crystal on the vacuum degree has been investigated by scanning force microscopy in the piezoresponse mode under high vacuum. Unusual piezo- response behavior related to the screening charges compensation mechanism is observed on the (111) crystal face. The significant piezoresponse degradation behavior with low piezoresponse signal under high vacuum is attributed to the instability of the polarization state due to the insufficient compensation of the intrinsic screening charges for the polarization charges in PMN-30%PT single crystal. In contrast, the remarkable domain contrast of the sample at ambient pressure is owing to the dominant surface screening charges deriving from surface adsorption, which plays an important role in determining the stability of the domain behavior and in achieving the optimal properties.展开更多
基金supported by the Flanders-China bilateral project(BIL 99/10)the Science and Technology Committee of Shanghai Municipalitythe Commission of the European Communities in the framework of the Growth Project"BIOGRAD"(G5RD-CT2000-00354)
文摘The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the isothermal sections of the ternary system at 1673 K and 1873 K is well reproduced. According to the assessed isothermal section at 1723 K, no alumina dissolves into the tetragonal zirconia phase. Specimens with different alumina content are fabricated from commercial 12 mol pct CeO2-stabilized ZrO2 powder (12Ce-ZrO2). The thermodynamic properties are consistent with the observed microstructure, which present a combination of tetragonal phase and alumina grains.
基金This work was supported by the Fund for Distinguished Young Scholars (Inorganic Chemistry No. 20025101)+1 种基金 Key Project from NNSFC (No.50332050) State "863" Project (No. 2002AA324070) and Fund of Shanghai Optical Science and Technology (No. 022261015)
文摘A microporous organically-templated tungsten heteropolyacid, (C2N2H10)2 [H2P2W18O62]?8H2O, with a new type was hydrothermally synthesized by using ethylenediamine as the structure-directing agent. Its structure was determined by single-crystal X-ray diffraction analysis. Crystal data: monoclinic, space group P21/c, a = 14.633(4), b = 19.432(5), c = 26.776(5) ?, β = 117.849(11)o, V = 6732(3) ?3, Z = 4, Mr = 4615.48, Dc = 4.554 g/cm3, μ(MoKα) = 30.781 mm-1, F(000) = 7976, the final R = 0.0678 and wR = 0.1359. The crystal of the title compound is constructed by Dawson anions and organic dications forming a novel “hollow” channel system.
基金This project was supported by the Foundation for Distinguished Young Scholars from the NNSF of China (No. 20025101)
文摘The title new compounds with chemical formula RNixBi2 were synthesized by arc melting method followed by annealing. The crystal structures refined by using Rietveld method and X-ray powder diffraction data are isotypic to CaMnBi2 structure type, space group P4/nmm with a = 0.448350(4), c = 0.930026(2) nm, V = 0.186952(7) nm3 for YNi0.82Bi2, a = 0.448882(5), c = 0.93658(2) nm, V = 0.188715(8) nm3 for GdNi0.86Bi2, a = 0.448486(3), c = 0.93062(2) nm, V = 0.187185(6) nm3 for TbNi0.78Bi2 and a = 0.447493(4) nm, c = 0.925852(1) nm, V = 0.185402(6) nm3 for DyNi0.77Bi2, showing lanthanide contraction. The structure is characterized by layers of edge-sharing NiBi4 tetrahedron and covalently bonded Bi square net separated by rare earth atoms.
基金This work was supported by the Natural Science Foundation (No. 20201013) and "Plan of Outstanding Talents" of the Chinese Academy of Sciences
文摘A novel metal organic compound of Zn2+ coordinated with 4,5-diazafluorene- 9-one-N2 (C22H12N6) has been synthesized under solvothermal condition. Single-crystal X-ray diffraction analysis showed that the compound is a one-dimensional zig-zag chain structure combined by Cl…H–C bonds. The crystal is of orthorhombic, space group Pnna, C22H12N6Cl2Zn, Mr = 496.65, a = 8.1132(13), b = 18.983(3), c = 13.116(2) ?, Z = 4, V = 2020.2(5) ?3, Dc = 1.633 g/cm3, μ = 1.504 mm-1, F(000) = 1000, T = 293(2) K, the final R = 0.0626 and wR = 0.1474 for 2390 unique reflections and 150 parameters with I > 2σ(I). The refinement method was full-matrix least-squares on F2 with GOF = 0.951. This compound was also characterized by FT-IR, Raman, UV-vis spectra, and TG-DTA.
基金supported by the National Natural Sciences Foundation of China(Grant No.59995520)the National“863”High Technology Research and Development Program of China(Grant No.2001AA325030)the National“973”Key Basic Program of China(Grant No.2002CB613307)
文摘The piezoresponse behavior dependence of the Pb(Mg1/3Nb2/3)O3-30%PbTiO3 single crystal on the vacuum degree has been investigated by scanning force microscopy in the piezoresponse mode under high vacuum. Unusual piezo- response behavior related to the screening charges compensation mechanism is observed on the (111) crystal face. The significant piezoresponse degradation behavior with low piezoresponse signal under high vacuum is attributed to the instability of the polarization state due to the insufficient compensation of the intrinsic screening charges for the polarization charges in PMN-30%PT single crystal. In contrast, the remarkable domain contrast of the sample at ambient pressure is owing to the dominant surface screening charges deriving from surface adsorption, which plays an important role in determining the stability of the domain behavior and in achieving the optimal properties.
