Preparation of high performance YGdBCO films by low fluorine TFA-MOD process

YBCO films doped with different contents of gadolinium(Gd) were prepared by the low-fluorine(low-F)trifluoroacetate metal-organic deposition(MOD) method.The effects of flow rate and holding time of the firing(crystallization) stage on the superconducting properties of YxGd1-xBa2 Cu3 O7-δ(YGdBCO) films were investigated.The phase formation and texture were characterized by the X-ray diffraction(XRD),which indicate that severe degradation of the microstructure will be induced with the inappropriate flow rate.The surface morphology and element distribution were investigated by the scanning electron microscopy(SEM) and energy dispersive spectroscopy(EDS).The results show that increasing the holding time of the firing stage is effective for the further decomposition of residual impurity phase on the surface.The mechanisms of the phase and surface evolution are also discussed.Finally,a high critical current density(Jc) value of 5.4 MA/cm2 was achieved in the Y0.9Gd0.1BCO film fabricated by the cooperative control of the flow rate and holding time of the firing stage,which are contributed to the formation of excellent texture,homogeneous microstructure and dense surface of the YGdBCO films.

化学溶液法制备超导薄膜的中间热处理研究

通过采用化学溶液沉积制备超导薄膜研究低温热解和高温晶化之间附加热处理过程,并比较这一过程对超导层成相、织构以及性能的影响。研究发现,中间热处理过程对超导层的织构有一定影响,合适的附加热处理过程有利于改善晶粒生长取向。当中间热处理温度为400℃时,超导层性能最佳(Jc=2.4MA/cm2)。