Synthesis, characterization and thermostability of barium β-diketonate with tetraethylenepentamine ligand
来源期刊：Rare Metals2012年第6期
论文作者：ZHANG Teng, GU Hongwei, DING Fazhu, QU Fei, and DAI Shaotao Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing , China
文章页码：566 - 572
摘 要：The metal-organic chemical vapor deposition （MOCVD） technique is a promising process for high-temperature superconductor YBa2Cu3O7-δ（YBCO） preparation. In this technique, it is a challenge to obtain barium precursors with high volatility. In addition, the purity, evaporation characteristics and thermostability of adopted precursors in the whole process would decide the quality and reproducible results of YBCO film. In the present report, the barium precursor containing 2,2,6,6-tetramethylheptane-3,5-dionate and tetraethylenepentamine ligands （Ba（TMHD）-tetraen） was synthesized and identified by FTIR, 1H NMR, 13C NMR and ESI-MS spectroscopy. Subsequently the thermal property and the kinetics of decomposition were systematically investigated by combining non-isothermal thermogravimetric analysis methods （TGA）, Ozawa, Kissinger and Friedman methods. On the basis of the apparent activation energy of the evaporation process, the thermostability and evaporation characteristics of the precursors were discussed. All results show that Ba（TMHD）-tetraen has higher volatility than Ba（TMHD）2, but it is unstable and highly sensitive to the change of temperature during the whole evaporation process. Therefore, it is very important to choose suitable volatilization technology and conditions for avoiding Ba（TMHD）-tetraen breakdown （or thermal aging） during the MOCVD process.
ZHANG Teng, GU Hongwei, DING Fazhu, QU Fei, and DAI Shaotao Key Laboratory of Applied Superconductivity, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing 100190, China
摘 要：The metal-organic chemical vapor deposition （MOCVD） technique is a promising process for high-temperature superconductor YBa2Cu3O7-δ（YBCO） preparation. In this technique, it is a challenge to obtain barium precursors with high volatility. In addition, the purity, evaporation characteristics and thermostability of adopted precursors in the whole process would decide the quality and reproducible results of YBCO film. In the present report, the barium precursor containing 2,2,6,6-tetramethylheptane-3,5-dionate and tetraethylenepentamine ligands （Ba（TMHD）-tetraen） was synthesized and identified by FTIR, 1H NMR, 13C NMR and ESI-MS spectroscopy. Subsequently the thermal property and the kinetics of decomposition were systematically investigated by combining non-isothermal thermogravimetric analysis methods （TGA）, Ozawa, Kissinger and Friedman methods. On the basis of the apparent activation energy of the evaporation process, the thermostability and evaporation characteristics of the precursors were discussed. All results show that Ba（TMHD）-tetraen has higher volatility than Ba（TMHD）2, but it is unstable and highly sensitive to the change of temperature during the whole evaporation process. Therefore, it is very important to choose suitable volatilization technology and conditions for avoiding Ba（TMHD）-tetraen breakdown （or thermal aging） during the MOCVD process.
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