涂层导体CeO_2过渡层的稳定性研究

Stability of CeO_2 Buffer Layer for Coated Conductor

采用反应溅射法制备涂层导体用CeO2过渡层,重点对不同水分压下制备的CeO2种子层,以及YBCO超导层沉积过程中CeO2帽子层的稳定性进行了分析。采用X射线分析相组成变化以及晶体取向,通过扫描电镜观察表面形貌。结果表明,水分压对CeO2生长影响较大,水分压太小会导致缺氧相CeO2-x(0<x<0.5)生成。虽然后续富氧退火处理能转变成CeO2,但由于体积变化会萌生裂纹,其薄膜完整性受到破坏。另外,高温的YBCO生长工艺亦会引起CeO2帽子层与YBCO反应生成BaCeO3,对后续的YBCO晶体取向和超导性能产生不利影响。

The CeO2 buffer layers were deposited on the NiW substrates using reactive magnetron sputte- ring. The stability of CeO2 seed layer under the vari- ous H20 partial pressure and cap layer during the dep- osition of YBCO film was studied in detail. The phase and crystalline orientation was analyzed by X-ray dif- fraction, and the surface morphology was observed by scanning electron microscopy. The results showed that the H2 0 partial pressure had great effect on the growth of CeO2. The small H20 partial pressure led to the formation of anoxie phase CeO2_x （0 〈 x 〈 0.5 ）. A1- though CeO2_x could transform into CeO2 after heat treatment in rich-oxygen ambience, the film was easy to crack due to the volume change. In addition, the BaCeO3 was caused by the reaction between YBCO and the CeO2 cap layer during the which might influence the crystalline performance of coated conductors YBCO growth, orientation and