Intermediate phase evolution in YBCO thin films grown by the TFA process
Intermediate phase evolution in YBCO thin films grown by the TFA process
复制标题
DOI：
10.1088/0953-2048/23/1/014012
复制
发表时间：
2009
影响因子：
3.6
通讯作者：
K. Zalamova;A. Pomar;A. Palau;T. Puig;X. Obradors
中科院分区：
文献类型：
--
作者：
K. Zalamova;A. Pomar;A. Palau;T. Puig;X. Obradors
TFA前驱体YBCO薄膜的生长过程是一个复杂的反应过程，包括氧化、氟和氧化氟中间相，这些中间相的形态和化学演化对薄膜的最终微观结构和性能有很大的影响。在这项工作中，我们提出了在常压条件下的TFA YBCO生长过程中涉及的中间相的演化研究，我们表明，在TFA前驱体热解过程中的氧分压是一个重要的参数。随着氧分压的改变，TFA热解后的Cu相可以是CuO或Cu2O，也可以是两者的混合物。测定了在氧和氮气氛下热解膜的中间相的动力学演变，得出非平衡相变影响YBCO外延膜的反应路径及其微观结构。在动力学相图中总结了这两个系列薄膜的中间相演化过程。
The YBCO thin film growth process from TFA precursors involves a complex reaction path which includes several oxide, fluoride and oxyfluoride intermediate phases, and the final microstructure and properties of the films are strongly influenced by the morphological and chemical evolution of these intermediate phases. In this work we present a study of the evolution of the intermediate phases involved in the TFA YBCO growth process under normal pressure conditions and we show that the oxygen partial pressure during pyrolysis of the TFA precursors is an important parameter. The Cu phase after the TFA pyrolysis can be either CuO, Cu2O or a mixture of both as the oxygen partial pressure is modified. The kinetics evolution of the intermediate phases has been determined for films pyrolysed in oxygen and nitrogen atmospheres and it is concluded that non-equilibrium phase transformations influence the reaction path towards epitaxial YBCO films and its microstructure. The intermediate phase evolution in these two series of films is summarized in kinetic phase diagrams.