真空调制YBCO超导电性的原理

The Modulation Principle of Vacuum on the Superconductivity of YBCO

用中子衍射等实验发观:在室温和低温真空条件下,YBCO样品结构中的氧也能扩散脱出体外,引起超导电性的显著下降。进一步还发现:在几天之内T_c随时间发生衰减振荡,真空度愈高,振幅愈大,周期愈短.初步认为T_(co)∞T_e^(-β1)cos(ωt+φ),并提出:在室温和低温真空下样品中可移动的离子氧和外部分子氧动态平衡决定T_c的原理。二者合称为T_c的振荡和动态平衡量原理。

By the experiments of neutron diffraction and other experiments, we have found that oxygen ions in YBCO can diffuse out of the sample in vacuum at room and low temperature, meanwhile the T decreases greatly. We have also found that if vacuum-deoxidation process lasts for several days, there will be a damping oscillation of T with time(t), and higher vacuum corresponds to greater amplitude and shorter period. We tentatively think that T, should satisfy the following function; TCD∝TCe-β' cos(ωt+ ), it may be due to the diffusion of oxygen and the saturation of valence state.