水基溶胶-凝胶沉积法制备YBCO薄膜

本文研究了退火温度对用水基溶胶-凝胶工艺在LaAlO₃ (100) 单晶衬底上沉积的YBCO 薄膜性能的影响。研究发现,随着温度的升高,薄膜的面内取向得到了优化,而薄膜的面外取向则不然。在 789 ℃退火的YBCO薄膜在77 K和0 T条件下的临界电流密度J_c达到了1.7 MA/cm²。而其他温度退火的薄膜的缺陷可能会导致YBCO超导电性变差。然而,这些薄膜中存在的残余应力应变也有助于增强其钉扎力并改善薄膜外加场下的电性能。

Preparation of YBCO Films by Water-Based Sol-Gel Deposition

The effects of annealing temperature on properties of YBCO films deposited on (100) LaAlO₃ single crystal substrates derived from a water-based sol-gel process were investigated. In this paper, the in-plane texture is improved at higher temperatures but the out-of-plane texture follows an opposite trend. YBCO films annealed at 789 ℃ with homogeneous and smooth surface as well as J_c=1.7 MA/cm² at 77 K and 0 T was obtained. Particles and holes observed on the other films could result in bad connections between superconducting grains and decrease the superconducting current in the films. Strain in these films is likely to enhance the pinning force and improve the transport properties under applied field.