Abstract The metal-organic chemical vapor deposition (MOCVD) technique is a promising process for high temperature superconductor YBa 2 Cu 3 O 7- d (YBCO) preparation. In this technique, the purity, evaporation characteristics and thermostability of adopted precursors will decide the quality and reproducible results of YBCO film. In the present report, tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium(III) (Y(TMHD) 3 ) was synthesized by the interaction of yttrium nitrate hydrate with TMHD in methanol solution, and its structure was identified by FTIR, 1 H NMR, 13 C NMR and EI-MS spectroscopy. Subsequently, the thermal property and the kinetics of decomposition were systematically investigated by non-isothermal thermogravimetric analysis methods (TGA) at different heating rates in streams of N 2 , and the average apparent activation energy of evaporation process was evaluated by the Ozawa, Kissinger and Friedman methods. The possible conversion function was estimated through the Coats-Redfern method to characterize the evaporation patterns and followed a phase boundary reaction mechanism by the contracting area equation with average activation energy of 88.9 kJ/mol.

中文翻译：

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三(2,2,6,6-四甲基-3,5-庚二酮)钇(III)的合成、表征和热稳定性

摘要 金属有机化学气相沉积（MOCVD）技术是制备高温超导体YBa 2 Cu 3 O 7-d（YBCO）的一种很有前景的工艺。在该技术中，所采用前驱体的纯度、蒸发特性和热稳定性将决定 YBCO 薄膜的质量和可重复性结果。在本报告中，三(2,2,6,6-四甲基-3,5-庚二酮基)钇(III) (Y(TMHD) 3 )是通过硝酸钇水合物与TMHD在甲醇溶液中的相互作用合成的，并且其结构经FTIR、 1 H NMR、 13 C NMR和EI-MS光谱鉴定。随后，通过非等温热重分析方法（TGA）系统地研究了 N 2 流中不同加热速率下的热性质和分解动力学，蒸发过程的平均表观活化能用Ozawa、Kissinger和Friedman方法评价。通过 Coats-Redfern 方法估计可能的转换函数以表征蒸发模式，并通过收缩面积方程遵循相界反应机制，平均活化能为 88.9 kJ/mol。