Double-sided high temperature superconducting tape was successfully developed

Today, superconducting technology is increasingly becoming an irreplaceable high-tech with economic strategic significance and great potential for development. It will have a tremendous boost to the development of the national economy and human society.

In recent years, a new generation of high-temperature superconducting tapes represented by YBa2Cu3O7-x (YBCO) has a higher magnetic flux pinning ability than the first-generation Bi-based tapes. Bi strip. At the same time, YBCO tape is a YBCO film grown on a flexible metal baseband to form a superconducting tape that can be wound, can carry large currents, and has a layered structure. Its carrier material is generally a nickel metal or alloy base tape, and no precious metal is needed. Material, so the cost of its preparation can be greatly reduced. At present, a new generation of high-temperature superconducting tapes has become a hot topic in superconducting materials research around the world.

The results show that the intergranular angle has a great influence on the critical current density of the YBCO film. When the grain boundary angle exceeds 5°, the current carrying capacity of the film decreases significantly. This requires that the superconducting layer in the strip structure has a relatively uniform grain arrangement. Neat, this makes the preparation conditions for high-performance YBCO long strips very demanding and must be prepared using a thin film deposition method. So far, various research institutes are continuously exploring to obtain YBCO tapes with lower cost, higher performance and longer length.

Researchers at the University of Electronic Science and Technology of China have recently developed a double-sided high-temperature superconducting tape. The tape is made of a buffer layer and a superconducting layer film on both sides of the alloy substrate. Because the thickness of the strip depends mainly on the baseband, if the buffer layer and the superconducting layer film can achieve good uniformity and double-sided consistency, the current carrying capacity of the strip can be doubled on almost the same thickness. Therefore, the successful development of the double-sided high-temperature superconducting tape is an important breakthrough in further reducing the production cost and improving the current carrying capacity of the strip.

They used the rolling-assisted biaxially textured baseband as the substrate, and used reactive sputtering to prepare double-sided Y2O3 double-sided seed layers. By introducing water vapor, Y atoms were oxidized and formed on the baseband, and oxidation of the baseband was effectively avoided. Through the optimization of the process parameters, they successfully prepared a high-quality Y2O3 seed layer with an internal and external orientation within a few degrees, which greatly improved the biaxial texture of the metal substrate. At the same time, the surface roughness of the film is only 2.8 nm. The YSZ barrier layer and CeO2 template layer were epitaxially grown on the prepared high-quality seed layer by a sputtering method, the film surface was smooth, and it had good uniformity and double-sided consistency. The YBCO superconducting layer was prepared by double inverted target sputtering method. The axially self-advancing and retreating of the film was performed by rotating and combining. The uneven heating of the film was improved, and a high-quality double-sided high-temperature superconducting tape was obtained. Among them, the sum of the currents Ic of the short face and the double face current exceeds 400 A/cm-w. At the same time, double-sided high temperature superconducting tapes with a length of more than 1 meter and Ic>210 A/cm-w have been successfully prepared. The existing results show that with the further improvement of the buffer layer preparation efficiency, it is expected to realize the large-scale production of high-performance superconducting 100-meter high-temperature superconducting tape in the near future.