热处理气氛中氧含量对YBCO薄膜性能的影响（英文）

Effect of Oxygen Content in Atmospheres of Heat Treatment on the Properties of YBCO Thin films

采用低氟溶胶-凝胶法在La Al O_3(100)基板上制备了YBa_2Cu_3O_(7-x)(YBCO)薄膜,研究了在725℃热处理过程中,氧含量对最终所得YBCO薄膜临界电流密度J c的影响。研究发现,热处理过程中氧气含量在100~1700μL/L范围变化时,所获得的YBCO薄膜均具有良好的双轴织构特征。然而,当氧气含量为100或200μL/L时,由于YBCO薄膜致密性差,不能获得高J c的YBCO薄膜。随着氧气含量的增大,YBCO薄膜表面逐渐变得致密。当氧气含量增加到300μL/L时,YBCO薄膜表面较致密,J c达到4.3 MA/cm^2。继续增大氧含量至800和1700μL/L,薄膜表面逐渐出现富铜第二相颗粒,成为其J c较低的主要原因。

YBa2Cu307-x （YBCO） films were prepared on single-crystal LaA103 （100） substrate using a low-fluorine sol-gel method. The effect of the oxygen content in the atmospheres of heat treatment at 725 ℃on the critical current density （Jc） of the obtained YBCO films was investigated. Results show that all the films heat-treated in the oxygen content range of 100-1700 μL/L exhibit good biaxial-texture characteristics. However, high-Jc YBCO films are not obtained at the oxygen contents of 100 and 200 μL/L due to the lower density of the surfaces. With increasing the oxygen content, the film surface becomes dense gradually. When the oxygen content is 300 μL/L, the surface of the film is very dense and Jc reaches 4.3 MA/cm^2. Furthermore, many copper-rich second phases grow up on the surfaces with further increasing oxygen content up to 800 and 1700 μL/L, which is a dominant reason for the decline in J0 of the films.