Tl-1223高温超导薄膜在蓝宝石单晶基片上的生长和性能研究

Growth and Properties of Tl-1223 High Temperature Superconducting Films on Sapphire Single Crystal Substrates

本文报道了采用射频磁控溅射法和快速升温烧结法在R面取向的蓝宝石单晶基片上生长CeO_(2)缓冲层和Tl-1223超导薄膜,研究了缓冲层生长情况和先驱膜后退火条件对超导薄膜结晶情况和超导特性的影响。AFM和XRD表征结果显示,蓝宝石基片经过退火后其表面形成具有光滑平台的台阶结构,同时基片的晶体质量得到了改善;本文所制备的CeO_(2)缓冲层和Tl-1223超导薄膜具有较好的c轴生长取向,而且两者呈现良好的ab面内织构。SEM表征结果显示,生长良好的Tl-1223超导薄膜呈层状结构,表面光滑平整、结构致密。在液氮环境下,测得所制备Tl-1223超导薄膜的临界转变温度Tc约为111 K,临界电流密度Jc(77 K,0 T)约为1.3 MA/cm2。

In this paper,the R-cut sapphire single crystal substrates were selected,and the CeO_(2) buffer layers were grown on the surfaces of substrates by RF magnetron sputtering method,then the high quality Tl-1223 superconducting films were grown by the rapid heating-up sintering technology.The effects of buffer layer growth and post annealing conditions of the precursor films on the crystallization and superconducting properties of the superconducting thin films were studied.AFM and XRD measurements show that the surface of sapphire substrates have a step structure with smooth platform and the crystal quality of sapphire substrates have been improved after annealing;the CeO_(2) buffer layers and the Tl-1223 superconducting films all have good c-axis growth orientation under appropriate parameters,and they exist a good ab-plane texture.SEM measurements show that the well grown Tl-1223 superconducting films have a layered structure and their surfaces are dense and smooth.The Tc of the prepared superconducting film is measured to be about 111 K,and Jc(77 K,0 T)is measured to be about 1.3 MA/cm2 in liquid nitrogen environment.