用俄歇电子能谱分析Y-Ba-Cu-O超导薄膜与衬底的界面互作用

高T_c的Y-Ba-Cu-O超导材料在弱电方面进入实用的一个重要条件,就是需要制备出优质的超导薄膜。已有多种制备超导薄膜的方法见报道。用蓝宝石或Si衬底制备超导薄膜,通常会由于薄膜与衬底强烈的界面反应使其零电阻温度大为降低,严重时甚至变成非超导。而我们在实验中发现,YSZ(掺钇稳定立方氧化锆)衬底在高温下与薄膜的界面反应也较为严重。在YSZ衬底上沉积一层Ag缓冲层则可以减轻薄膜与村底的相互作用。

INVESTIGATION OF INTERACTION BETWEEN SUBSTRATE AND YBa2Cu3O7-δ SUPERCONDUCTING THIN FILM BY AES

The interaction between superconducting thin film of YBa_2Cu_3O_(7_δ) and substrate Of YSZ (Yttric stabilized zirconia) was investigated by AES. It is found after annealing at 900 ℃ that Ba and Cu atoms in the film severely diffuse to and interact with the substrate, white Zr atoms of the substrate do to and with the film, moreover,the diffusion of Ba atoms is more rapid than that of Cu atoms. A thin Ag film deposited on the substrate as a buffer layer seperates the defects on the surface of substrate from the film to suppress the formation of the second phases at the substrate defects as nucleation centre and retard the diffusion of Ba and Cu atoms to the substrate, and lessen the segregation of Cu and CuO in the film.