【摘要】 采用直流磁控溅射法和后退火技术在蓝宝石基片上制备了Tl-2212超导薄膜,考察了Tl-2212薄膜的厚度对其形貌和超导特性的影响。实验结果表明,随着超导薄膜厚度增加,其表面形貌由致密平整的结构演化为片状晶体结构,临界转变温度Tc和临界电流密度Jc先增大后减小,微波表面电阻Rs先减小后增大。在退火的CeO2缓冲层上所制备的无裂纹薄膜的最大厚度达到600nm,并仍然具有良好的超导性能。更多还原

【Abstract】 Tl-2212 high temperature superconducting(HTS) films were prepared on r-cut sapphire substrates buffered with CeO2 by dc magnetron sputtering technique and post-annealing process.The effects of various thicknesses of Tl-2212 films on their surface morphologies and superconducting properties were investigated.The results show that with increasing of the superconducting film thickness,the dense surface morphology evolves into flake-like crystal structure,the critical temperature Tc and critical current density Jc increase and then decrease,and the microwave surface resistance Rs decreases and then increases.The maximum thickness limitation of the crack-free Tl-2212 films,with CeO2 buffer layers annealed,reaches to 600 nm.The films possess excellent superconducting properties.更多还原