YBa_2Cu_3O_(7-y)-BaPbO_3体系的相结构和超导电性

THE PHASE STRUCTURE AND SUPERCONDUCTIVITY OF YBa_2Cu_3O(7-y)-BaPbO_3 SYSTEM

实验证明,在YBa_2Cu_3O_(7-y)-BaPbPO_3体系中,两相以混合态存在,Pb基本没有取代Y-Ba-Cu-O中的元素,BaPbO_3的含量小于10%时对Y-Ba-Cu-O的r_c没有影响,只使其临界电流J_c增加;当BaPbO_3的含量为10%时,J_c是纯YBa_2Cu_3O_(7-y)的3.5倍。结构分析表明,BaPbO_3的存在使YBa_2Cu_2O_(7-y)晶体沿c方向产生定向排列。故而认为,BaPbO_2可能是制做YBa_2Cu_3O_(7-y)薄膜的良好衬底。

Experimental results demonstrate that in the system of YBa_2Cu_3O_(7-(?))-BaPbO_3, the two phases exist in a mixed state, Elements in Y-Ba-Cu-O system are not substituted by Pb basieally. The existence of BaPbO_3 less than 10% has no influence on T_α of Y-Ba-Cu-O, but makes J_c increase. When BaPbO_3 content is 10%, J_c increases to 2.5 times more than that of pure Y-Ba-Cu-O. Structure analysis shows that the existence of BaPbO_3 causes the orientation growth of YBa_2Cu_3O_(7-y) along c axis. So it is considered that BaPbO_2 may be a good substrate material for growing YBa_2Cu_3O_(7-y) thin fiTm.