Growth condition related orientation transition for YBa<sub>2sub>Cu<sub>3sub>O<sub>7鈭?span style='font-style: italic'>未sub> films on NdGaO<sub>3sub> substrate
- 作者：Y.Y. Chen<sup>asup> ; L.S. Guo<sup>asup> ; Y.Q. Cai<sup>asup> ; C.Y. Tang<sup>asup> ; S.B. Yan<sup>asup> ; X. Yao<sup>asup><sup> ; sup><sup>bsup><sup> ; sup><sup>xyao@sjtu.edu.cnsup> ; R. Puzniak<sup>csup>
- 关键词：A1. Etch-back ; A1. Out-of-plane orientation transition ; A3. Liquid-phase epitaxy ; B1. YBCO ; B2. Oxide superconducting materials
- 刊名：Journal of Crystal Growth
- 出版年：2012
- 期刊代码：49_00220248
- 类别：ch
- 出版时间：15 May, 2012
- 卷：347
- 期：1
- 页码：82-87
- 文件大小：962 K
摘要
For comprehensive understanding, the crystallographic out-of-plane axis transition for YBa<sub>2sub>Cu<sub>3sub>O<sub>7鈭?em>未sub> (YBCO or Y123) films grown on (110) NdGaO<sub>3sub> (NGO) substrate, using liquid phase epitaxy (LPE), was systematically investigated via changing flux composition, processing temperature and oxygen partial pressure. It is found that LPE films could grow, remarkably, in a wide temperature range between 24 K above and 25 K below the peritectic temperature (T<sub>psub>). The unpredicted c-oriented films formed at the temperatures above T<sub>psub>, is deduced to be attributed to the etch-back behavior, i.e., Nd partially dissolved from the NGO substrate into solution, which leads to a locally high supersaturation for facilitating film growth. Even more distinctively, decreasing from the high temperature in this wide range, the YBCO films characteristically experienced the orientation transitions, the double transition of the c-axis oriented鈫?em>a/c-axis mixed鈫?em>c-axis oriented in air, and a single evolution of the c-axis鈫?em>a-axis in the pure oxygen atmosphere. By combining supersaturation with the NGO etch-back, and solute diffusion, the transition origin of the film orientation in various temperature regions was clarified.