摘要
报道了对光辐照YBa_2Cu_3O_6.92材料的正电子寿命谱研究结果，给出了正电子寿命参数随辐照时间变化的基本特征，利用两态捕获模型对实验结果进行了初步分析，计算了局域电子密度尼和空位浓度已随辐照时间的变化，发现光诱导而产生Cu－O链区域电子结构的变化，证明O（1）和0（5）位之间的氧迁移和重新分布使得氧有序乃是光诱导电性的主要原因，为YBa_2Cu_3O_6.92体系光电导机理的理解提供了重要的正电子实验证据。
The results of positron lifetime forYBa_2Cu_3O_6.92with the different photo-irradiations time is presented. The positron lifetime parameters is given as a function of the irradiation time. Using the two-state trapping model,the local electron dens1ty n, and the vacancy concentration C. are evaluated as a function of the pho to-lrradiat1on time- The electronic structure change in the Cu-O chains region by photo-in duction is found' The effect mechanism of the photo-induction on Y(l23) systems and the relation between the oxygen-order and its re-distribution in Y (123) lattice are also dis ctlssed.
出处
《光电子技术》
CAS
1998年第2期143-148,共6页
Optoelectronic Technology
基金
国家超导攀登计划课题
河南省自然科学基金
关键词
光电导效应
超导体
正电子湮没谱
photo-irradiation effect,YBa_2Cu_3O_(6.92), ceramics, positron lifetime
