高温超导薄膜电子显微结构的研究

Studies of High Temperature Superconducting Thin Films by Electron Microscopy

本文报导了超导实验室用H9000NA分析型电镜观察高温超导薄膜的结果,表明:激光淀积的YBCO薄膜易于出现非超导的大颗粒,提高了薄膜的表面微波电阻。但工艺若掌握得好时可生成单晶薄膜,适用于无源微波器件。磁控溅射的YBCO/STO/YBCO三层膜需要控制好底YBCO层的生长温度,使膜中无α-取向晶粒出现,由于α-取向晶粒生长速度数量级的快于c-取向膜,而穿透STO导致漏电。LAO基片的质量不好,生长的T1-2212薄膜的质量也不好,缺陷及孔洞较多,并生有LAO/膜的非晶过渡层,超导性能不好;超导性能好的T1-膜正在观察中。

High temperature superconducting thin films have been studied in the Supercoconducting Laboratory by H9000NA analytical electron microscope. TEM observations showed many non-superconducting particles formed on this YBCO thin films prepared by laser ablation which increased the surface microwave resistance of the film. However, if the ablation process is controlled properly, epitaxial single crystalline YBCO thin film could be ob-tained, which is suitable for the use of planar passive microwave devices. The YBCO/STO/YBCO prepared by D. C./R. F. magnetron sputtering showed less particles, but the preparation of the lower YBCO layer result should be carefully controlled so that no a-oriented YBCO particle will form,which grows much faster than the c-oriented YBCO film and will penetrate the STO insulate layer result shorting. The LAO substrate for growing T1-2212 film showed many defects, the quality of the T1-2212 was very poor, so was the superconducting proper-ty. A T1-2212 film with good superconducting property is now under TEM observation.