低温热处理对TFA—MOD技术制备YBCO超导薄膜的影响.docx

低温热处理对TFA-MOD技术制备YBCO超导薄膜的影响/张云等·15·

低温热处理对TFA-MOD技术制备YBCO超导薄膜的影响*

张云1,张国防1,金利华2,王耀2,于泽铭2,李成山2,卢亚锋

(1陕西师范大学化学与材料科学学院应用表面与胶体化学教育部重点实验室，西安710062;

2西北有色金属研究院，西安710016)

摘要采用三氟乙酸盐-金属有机沉积(TFA-MOD)技术在LaAlO?(001)单晶衬底上沉积YBa?Cu?O?-(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J.可超过2.0MA/cm2。

关键词YBCO超导薄膜TFA-MOD技术涂覆环境相对湿度升温速度

InfluenceofLow-temperatureHeatTreatmentonYBCOSuperconductingFilmsPreparedbyTFA-MOD

ZHANGYun1,ZHANGGuofang1,JINLihua2,WANGYao2,YUZeming2,

LIChengshan2,LUYafeng2

(1KeyLaboratoryofAppliedSurfaceandColloidChemistryofMinistryofEducation,SchoolofChemistryMaterialsScience,ShaanxiNormalUniversity,Xian710062;2NorthwestInstituteforNonferrousMetalResearch,Xian710016)

AbstractTheYBCOsuperconductingfilmsaredepositedonLaAlO?(001)singlecrystalsubstratesbyTFA-MOD.Theinfluenceofcalciningconditions(relativehumidityduringcoatingandheatingrate)ongrowthofYBCOprecursorfilmsareinvestigated.Basedontheopticalmicroscope(OM)andscanningelectronmicroscopy(SEM)ob-servations,theresultsshowthatmacro-cracksinprecursorfilmsarecausedbyhighrelativehumidityofthecoatingenvironment.Thesurfacebucklingandmicro-cracksappearduetotoofastdecompositionrateofprecursorfilm.Theimperfectionsofprecursorfilmwillaffectphaseformation,morphologyandfinallysuperconductingpropertiesoftheYBCOfilms.Withoptimizationofcalciningconditions,theprecursorfilmswithexcellentsurfacemorphologycanbeobtainedandtheformationofimpurityphasesformationcanbeavoidedinfiringprocess.TheJ。offilmsishigherthan2.0MA/cm2at77K.

KeywordsYBCOsuperconductingfilm,TFA-MOD,