Since the discovery of superconductivity of the BiSrCuO system at 20K, the work of synthesizing high Tc superconductors without rare-earths by adding some elements other than rare-earths in the BiSrCuO system has made...Since the discovery of superconductivity of the BiSrCuO system at 20K, the work of synthesizing high Tc superconductors without rare-earths by adding some elements other than rare-earths in the BiSrCuO system has made a lot of progress. Recently, N. Fukushima et al. have synthesized Bi4Sr4RE2Cu4O16+δ (RE = Nd, Eu or Y) by substituting RE for Ca in the Bi4Sr4Ca2Cu4O16+δ superconductor and revealed that it has a crystal structure identical with this superconductor, but it is an insulator. In this paper, the authors report the superconductivity and structure of the BiSrCaEuCuO compound synthesized by adding 5 at% of rare-earth Eu in the BiSrCaCuO system.展开更多
A novel luminescent coordination compound Eu（TTA）3（DEDAF）（1, TTA = 1,1,1-trifluoro-3-（2-thenoyl）acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren） has been synthesized and fully characterized by infrared spectrum,...A novel luminescent coordination compound Eu（TTA）3（DEDAF）（1, TTA = 1,1,1-trifluoro-3-（2-thenoyl）acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren） has been synthesized and fully characterized by infrared spectrum, elemental analysis, UV-vis spectrum, etc. X-ray single-crystal diffraction analysis reveals that compound 1 shows a mononuclear structure with the europium atom in coordinating to one DAF and three TTA ligands. The mononuclear structure units are assembled into a 3-D polymer by hydrogen bonds and π-π interactions. Photoluminescent property of 1 was investigated in detail at room temperature. Complex 1 emits strong red luminescence. However, it could be quenched even by small amount of water. The fluorescence intensity at 614 nm decreases linearly with the water content increasing（vol% in acetonitrile） in the range of 0.025~0.2% under 278 nm excitation. Thermogravimetric analysis has also been studied, which demonstrates good thermal stability of 1.展开更多
In the last years the development of new luminescent materials was grow highly in order to find efficient materials with low cost of processing. In this way the organic luminescent materials have special attention bec...In the last years the development of new luminescent materials was grow highly in order to find efficient materials with low cost of processing. In this way the organic luminescent materials have special attention because its special characteristics, like antenna effect, low temperature processing, possibility to make translation to polymeric and flexible compounds. In this work luminescent powders of TTA:Eu3+ by sol-gel method were synthesized in order to define the synthesis parameters of the highest luminescence. The temperatures of heat treatment were 80°C, 100°C, 200°C and the concentration of Europium where 10%, 20%, 30% and 40% mol (TTA-10Eu, TTA-20Eu, TTA-30Eu, and TTA-40Eu). Fourier Transform Infrared Rays analysis (FTIR) and emission luminescence measures, the best conditions of synthesis were obtained at 40% mol of Europium and 80°C of heat treatment, at 272 nm of excitation. All the samples present the corresponded Eu3+ ion transitions the 5D0 → 7FJ (J = 0, 1, and 2). This confirms the great possibilities of these materials for optoelectronic applications.展开更多
文摘Since the discovery of superconductivity of the BiSrCuO system at 20K, the work of synthesizing high Tc superconductors without rare-earths by adding some elements other than rare-earths in the BiSrCuO system has made a lot of progress. Recently, N. Fukushima et al. have synthesized Bi4Sr4RE2Cu4O16+δ (RE = Nd, Eu or Y) by substituting RE for Ca in the Bi4Sr4Ca2Cu4O16+δ superconductor and revealed that it has a crystal structure identical with this superconductor, but it is an insulator. In this paper, the authors report the superconductivity and structure of the BiSrCaEuCuO compound synthesized by adding 5 at% of rare-earth Eu in the BiSrCaCuO system.
基金supported by the Natural Science Foundation of Zhejiang Province(No.LY16B030009)National Natural Science Foundation of China(No.61205184)521 Talent Cultivation of Zhejiang Sci-Tech University(521 talent project of ZSTU)
文摘A novel luminescent coordination compound Eu（TTA）3（DEDAF）（1, TTA = 1,1,1-trifluoro-3-（2-thenoyl）acetone, DEDAF = 9,9-diethyl-4,5-diazafluoren） has been synthesized and fully characterized by infrared spectrum, elemental analysis, UV-vis spectrum, etc. X-ray single-crystal diffraction analysis reveals that compound 1 shows a mononuclear structure with the europium atom in coordinating to one DAF and three TTA ligands. The mononuclear structure units are assembled into a 3-D polymer by hydrogen bonds and π-π interactions. Photoluminescent property of 1 was investigated in detail at room temperature. Complex 1 emits strong red luminescence. However, it could be quenched even by small amount of water. The fluorescence intensity at 614 nm decreases linearly with the water content increasing（vol% in acetonitrile） in the range of 0.025~0.2% under 278 nm excitation. Thermogravimetric analysis has also been studied, which demonstrates good thermal stability of 1.
文摘In the last years the development of new luminescent materials was grow highly in order to find efficient materials with low cost of processing. In this way the organic luminescent materials have special attention because its special characteristics, like antenna effect, low temperature processing, possibility to make translation to polymeric and flexible compounds. In this work luminescent powders of TTA:Eu3+ by sol-gel method were synthesized in order to define the synthesis parameters of the highest luminescence. The temperatures of heat treatment were 80°C, 100°C, 200°C and the concentration of Europium where 10%, 20%, 30% and 40% mol (TTA-10Eu, TTA-20Eu, TTA-30Eu, and TTA-40Eu). Fourier Transform Infrared Rays analysis (FTIR) and emission luminescence measures, the best conditions of synthesis were obtained at 40% mol of Europium and 80°C of heat treatment, at 272 nm of excitation. All the samples present the corresponded Eu3+ ion transitions the 5D0 → 7FJ (J = 0, 1, and 2). This confirms the great possibilities of these materials for optoelectronic applications.
