本文通过脉冲激光沉积法制备了不同厚度（80nm、320nm、1000nm和2000nm）的YBa2Cu3O7-δ（YBCO）超导薄膜，对它们的剩余应力和临界电流特性进行了对比研究．通过系列的激光显微Raman光谱和磁化曲线测量分别获得了薄膜剩余应力和磁化临界电流密度（Jc）对薄膜厚度的依赖关系．结果显示超导薄膜内剩余应力越小，Jc越高．对于中等厚度的薄膜样品（320nm和1000nm），其膜内剩余应力较小，同时由其特征的磁通匹配场大小推知在该厚度范围内的样品具有较高的线性缺陷密度，从而显示出较高的Jc值．
A series of YBa2Cu3O7-δ(YBCO) epitaxial films with different thicknesses (80 nm, 320nm, 1000nm and 2000 nm) are prepared by using pulsed laser deposition (PLD) and their critical current characteristics and internal residual stress are studied. Internal residual stress and critical current density for the films can be obtained by means of Laser Raman spectra and magnetic measurement. The result shows that the less residual stress, the higher Jc. The samples with moderate thickness (320nm and 1000nm) have higher Jc due to their less residual stress and higher liner defects density analysed by the result of their accommodation fields.
参考文献
| [1] | K Develos-Bagarinao;H Yamasaki;J C Nie .Thickness dependence of J_c for YBCO thin films prepared by large-area pulsed laser deposition on CeO_2 -buffered sapphire substrates[J].Superconductor Science & Technology,2005(5):667-674. |
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