Grown on the (a) CeO2, (b) YSZ/CeO2, and (c) CeO2/YSZ/CeO2 buffer architectures. To verify whether LZO buffer layer was suitable for the epitaxial growth of YBCO superconducting film, YBCO-coated conductors were deposited on highly textured LZO/CeO2, LZO/YSZ/CeO2, and LZO/CeO2/YSZ/CeO2 buffer architectures. The I c of YBCO films on the LZO/CeO2, LZO/YSZ/CeO2, and LZO/CeO2/YSZ/CeO2 buffer architectures were measured at 77 K and self field by the conventional four-probe method without microbridge patterning shown in Figure 6. The critical current density was calculated from J c = I c /(a × b) (a and b are the film width and thickness GW786034 datasheet in SHP099 ic50 centimeters, respectively). From the voltage–current

characteristic curves, the I c of YBCO films were recorded by using the criterion of 1 μV/cm. Figure 6 shows that the I c of YBCO films grown on the LZO/CeO2, LZO/YSZ/CeO2, and LZO/CeO2/YSZ/CeO2 buffer architectures are 140, 100, and 60 A/cm, respectively. The thicknesses of YBCO films grown on the LZO/CeO2, LZO/YSZ/CeO2, and LZO/CeO2/YSZ/CeO2 buffer architectures are all

the same which is 500 nm. As expected, the highest J c of 2.8 MA/cm2 at 77 K, self field is obtained for YBCO-coated conductor grown on LZO/CeO2 buffered Ro-3306 NiW tape. Therefore, the highly textured LZO film grown on CeO2-seed buffered NiW tape, which has smooth surface without any island and crack, is suitable for the epitaxial growth of high-performance YBCO-coated conductors. Figure 6 End-to-end voltage–current characteristics

of YBCO-coated conductors. Deposited on the LZO/CeO2, LZO/YSZ/CeO2, and LZO/CeO2/YSZ/CeO2 buffered NiW tapes using the conventional four-probe method tested at 77 K and self field. Conclusions LZO films were grown on CeO2, YSZ/CeO2, and CeO2/YSZ/CeO2 buffered RABiTS tapes by RF magnetron sputtering. As a result, LZO films prepared on the single CeO2 and CeO2/YSZ/CeO2 buffer architectures were preferentially c-axis-oriented and highly textured. Only small LZO (222) peak was observed in the LZO film fabricated on YSZ/CeO2 buffered NiW tape. Both in-plane and out-of-plane textures of LZO film on the CeO2-seed buffered Flavopiridol (Alvocidib) NiW tape were ∆ φ = 5.5° and ∆ ω = 3.4°. LZO films had very smooth surfaces, but microcracks were observed in LZO films grown on the YSZ/CeO2 and CeO2/YSZ/CeO2 buffer architectures. From the results discussed above, LZO film on CeO2-seed buffered NiW tape had the smoothest surface with the smallest RMS value and best in-plane and out-of-plane textures. The highly textured LZO film grown on CeO2-seed layer with smooth surface satisfied the requirements of epitaxial growth of YBCO-coated conductors with high currents. Acknowledgments This research is sponsored by the Ministry of Science and Technology of China (under 863 project grant no. 2009AA032402), the Youth Fund of Natural Science Foundation of China (grant no. 11204174), the International Thermonuclear Experimental Reactor (ITER) Plan (grant. no.