摘要
系统研究了不同氧缺陷的YBa_2Cu_3O_(7-δ)(δ=0.06—0.68)超导体正常态(300K)和超导态(77K)下的正电子寿命谱,利用两态捕获模型对实验结果进行了分析,计算了相应的局域电子密度n_c和空位浓度C_v随氧缺陷δ的变化,给出了氧缺陷YBa_2Cu_3O_(7-δ)体系的正电子湮没特征,讨论了相应的正电子湮没机制以及与超导电性之间的关联。
Positron lifetime spectroscopy has been used for studying various oxygen-defici ent YBa2Cu3O7-δ (δ=0.06-0.68) at normal state (300 K) and Superconducting state (77 K). Using the two-stste trapping model, the experimental results were analysed and there exists a typical positron annihilation characteristics in this systems. The local electron density nc and vacancy concentration Cv are calculated as a function of oxygen-deficiency δ. The mechanism of positron annihilation and the correlati-on with superconductivity are also discussed.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
1995年第6期929-935,共7页
Acta Physica Sinica
基金
河南省自然科学基金资助的课题
