We have successfully employed metal-organic chemical vapor deposition(MOCVD)technique to simultaneously deposit double-sided YBa2Cu3O7-δ(YBCO)films on both sides of Y2O3/yttria-stabilized zirconia(YSZ)/CeO2(YYC)buffered biaxially textured Ni-5 at.%W substrates,which is of great prospect to cut the production cost of YBCO coated conductors.X-ray diffraction analysis revealed that both sides of YBCO film were purely c-axis oriented and highly textured.Theφ-scan of(005)YBCO andφ-scan of(103)YBCO yielded full width at half maximum(FWHM)values of 4.9°and 6.6°for one side of double-sided YBCO film,respectively,as well as 4.4°and 6.4°for the other side.The current transportation measurements performed on such double-sided 500 nm-thickness YBCO films showed the self-field critical current density(Jc)at 77 K of0.6 MA/cm2 and 1.2 MA/cm2,respectively.Further research is in the process of exploring new solution to improve the Jc in practice.
Single-layer YBa2Cu3O7-d(YBCO) films with the thickness of over 600 nm were fabricated by modified metal organic deposition using trifluoroacetate metal organic deposition(TFA-MOD) method on LaAlO3(LAO) substrates. Polyvinylbutyral(PVB) was added into the precursor solution to enhance the thickness of the single layer. The pyrolysis process was shortened to about 3 h due to the reduction of the fluorine content in the precursor solution.The effects of heating rate during the crystallization process on the microstructure and Jcvalues of YBCO films were investigated. The a-axis-oriented YBCO crystals dominate when the heating rate is lower than 20 °Cámin-1, while faster heating rate of 43 °Cámin-1results in pure c-axis epitaxial growth. The Jcvalues of YBCO films increase linearly with heating rate increasing due to the increase of c-axis YBCO growth, and the critical current(Ic) value of 100 Aácm-1within a single-layer YBCO film is achieved.
Pei GuoXiao-Hui ZhaoJie XiongXing-Zhao LiuBo-Wan Tao
