中文摘要：

采用高温金相显微镜，实时观察RBa2Cu3Oz（RBCO, R代表稀土元素）薄膜的熔化过程.结合X射线衍射（XRD）极图的分析，对不同面内取向和面外取向的RBCO薄膜熔化行为进行横向比较，研究了RBCO微结构对于其热稳定性的影响，并用半共格界面能理论很好地解释了XRD分析和实时观察熔化过程的实验结果.对不同面内取向YBa2Cu3Oz（YBCO）薄膜的研究结果表明，空气中0°晶粒的热稳定性优于45°晶粒；此外还研究了c轴取向的SmBa2Cu3Oz（SmBCO）薄膜的热稳定性，结果表明微量a轴晶粒对SmBCO薄膜的熔化行为以及其热稳定性有明显影响.

英文摘要：

Appling high temperature optical microscopy （HTOM）, the in-situ observations on the melting process of RBa2Cu3Oz（RBCO） oxide thin films were carried out. Combined the X-ray diffraction （XRD） pole figures with the scanning electron microscope （SEM）, the microstructure of RBCO thin films with different in-plane and out-of-plane orientations were studied. The relationship between the thermal stability of RBCO thin film and its microstructure was investigated. The conclusions of semi-coherent interface energy theory is in good agreement with the experimental results from HTOM, SEM and XRD. It is evident that the thermal stability of 0° in-plane YBCO grain surpasses the 45° one in the air. Additionally, it was found that a very small volume percentage of a-axis grain has an obvious influence on the decomposition behavior and thermal stability of SmBCO film.