涂层导体用YBa_2Cu_3O_(7-x)/SrRuO_3准多层膜结构的磁传输特性研究

Magnetotransport Properties of YBa_2Cu_3O_(7-δ)/SrRuO_3 Quasi-multilayers

使用脉冲激光沉积工艺在SrTiO3基片上制备两类由超导层Y123和导电的SrRuO3组成的准多层膜。膜的名义结构分别是p×[Y123(m)/SrRuO3(n)](m,n分别代表各层膜的脉冲数,p代表重复周期)和p×[SrRuO3(n)/Y123(m)]。X射线衍射表明:准多层膜的面内及面外织构都同纯的Y123薄膜相当。随着SrRuO3膜的厚度的增加,伴随有SrRuO3峰的强度减弱以及异质相Ba2YRuO6的产生,样品的超导转变温度逐渐降低。磁传输特性显示70、77K时,准多层膜表现出优于纯的Y123的强磁通钉扎性能。温度为70K,磁场为8T时,多层膜的临界电流密度超过1.2×105A/cm2,是纯的Y123的2倍,表现出良好的应用前景。

A series of quasi-multilayers of YBa2Cu3O7-δ/SrRuO3, namely p×（YBCO（m）/SrRuO3 （n）） （p： repetition periods, m： YBCO pulse number, and n：SrRuO3 pulse number）, were prepared on single crystal SrTiO3 by pulsed laser deposition. X-ray diffraction measurements reveal that both in-plane and out-of-plane textures of all the present quasi-multilayers are as good as pure YBCO. With increasing SrRuO3 pulse number, the intensity of YBCO（00l） peaks are reduced and the sample forms heterogeneous phase Ba2YRuO6. And the superconducting transition temperature （Tc） decreases with increasing of SrRuO3 pulse number. There is no big difference in their superconducting transition temperature （Tc） between these two samples. The magnetic properties shows a better pinning property of quasi-multilayers, compared to pure YBCO at 70K and 77 K. Critical current density （Jc） of sample at 8T and 70 K reveals a value of higher than 1.2×105A/cm^2, two times as pure YBCO, showing very good application foreground.