YBCO高温超导带材熔融行为研究

Melting behavior of YBCO high temperature superconducting tape

对于第二代高温超导带材,超导接头的实现与超导层的直接熔融互连有关。为了研究YBa2Cu3O7-x(YBCO)高温超导带材在热处理时的熔融行为,在真空下对一段梯形的YBCO带材通电使其形成不同的温区,通过不同的测试手段研究薄膜经过热处理后成分、结构以及超导性能的变化。结果表明YBCO超导层在经过一个合适的温度和4h的氧气退火处理后,能够恢复或部分恢复其超导性能。经分析认为此过程中超导薄膜能够恢复超导性能的原因是Y123相没有分解。但是,如果热处理温度过高会导致Y123相分解为Y211相和钡铜氧化物,这种相变会导致超导性能无法恢复。

For the second-generation high temperature superconducting tape, the realization of superconducting joint is related to the direct melting connection of the superconducting layer. In order to study the melting behavior of YBa2Cu3O7-x high-temperature superconducting tape, a heating current was introduced into a trapezoidal YBCO tape under vacuum to obtain different temperature zones. The composition, structure and superconducting properties of the film were studied with different test methods. The results show that the superconducting performance of YBCO films can recover or partially recover after the treatment of a suitable heating current and 4 h oxygen annealing. The reason for the recovery of superconducting performance is probably that Y123 crystal does not decompose in this process. However, if the heating temperature is too high, Y123 superconducting phase will decompose into Y211 phase and barium copper oxide, which may lead to the deterioration of superconducting properties.