摘要
采用正电子湮没技术测量了不同氧含量的Y_1Ba_2Cu_3O_(6+8)(0<δ<1.0)系超导陶瓷的正电子寿命谱。发现正电子寿命随氧含量增加,呈现非单调的变化,根据正电子理论对其进行了分析。结果表明:正电子寿命能灵敏地反映出氧在Cu-O链上填充的有序—无序转变以及正交相—四方相的结构相变。这也表明了正电子湮没技术可能是研究高温超导陶瓷的一个有力工具。
The positron lifetime spectra of Y1Ba2Cu3O6+δ samples with different oxygen contents were measured. The relationship between positron lifeline and the oxygen vacancy in the ceramics was discussed based on the positron annihilation theory. The results indicated that the order-disorder transition of the oxygen filling in Cu(1)-O chains and the orthorhombic-tetragonal structural phase transition can be sensitively reflected by the positron annnihilation spectrum. It is clear that the positron annihilation technique is one of the most effective tools to study the high Tc oxide superconductors.
关键词
超导陶瓷
正电子湮没
YBACUO
superconducting ceramics,oxygen vacancies, positron annihilation technique
