摘要
采用三氟乙酸盐-金属有机沉积(TFA-MOD)技术在LaAlO3(001)单晶衬底上沉积YBa2Cu3O7-x(YB-CO)超导薄膜,研究了低温热处理条件(涂覆环境相对湿度和升温速度)对前驱膜形貌和YBCO超导膜的影响。从金相显微镜(OM)和扫描电镜(SEM)观察可以看出,高涂覆环境相对湿度是引起前驱膜出现宏观裂纹的主要原因,前驱膜分解速度过快会造成薄膜中出现褶皱和微观裂纹,前驱膜出现不完整性形貌将会影响YBCO薄膜的成相、形貌和性能。通过优化低温热处理条件,获得了表面形貌完整的前驱膜,避免了在高温成相阶段中出现杂相,提高了涂层导体的超导性能,77K时Jc可超过2.0MA/cm2。
The YBCO superconducting films are deposited on LaAlO3 （001） single crystal substrates by TFA- MOD. The influence of calcining conditions （relative humidity during coating and heating rate） on growth of YBCO precursor films are investigated. Based on the optical microscope（OM） and scanning electron microscopy（SEM） observations, the results show that macro-cracks in precursor films are caused by high relative humidity of the coating environment. The surface buckling and micro-cracks appear due to too fast decomposition rate of precursor film. The imperfections of precursor film will affect phase formation, morphology and finally superconducting properties of the YBCO films. With optimization of calcining conditions, the precursor films with excellent surface morphology can be obtained and the formation of impurity phases formation can be avoided in firing process. The Jc of films is higher than 2.0MA/cm2 at 77K.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2010年第8期15-18,28,共5页
Materials Reports
基金
国家863计划项目(2006AA03Z204
2008AA03Z201)
