双面Tl-2223高温超导薄膜的制备研究  

A new method for preparing double-sided Tl-2223 HTS films

作　　者：赵海廷 梁雪连 陈纪煌 杨骞 季鲁[1] 何明[1] Zhao Haiting;Liang Xuelian;Chen Jihuang;Yang Qian;Ji Lu;He Ming(College of Electronic Information and Optical Engineering,Nankai University,Tianjin 300350,China)

机构地区：[1]南开大学电子信息与光学工程学院,天津300350

出　　处：《低温与超导》2024年第3期16-23,63,共9页Cryogenics and Superconductivity

基　　金：国家自然科学基金(61771099,51002081,12074195)资助。

摘　　要：本文提出了一种改进的两步法在2英寸LaAlO_(3)(00l)衬底上制备双面Tl_(2)Ba_(2)Ca_(2)Cu_(3)O_(10)(Tl-2223)高温超导薄膜,通过特制蓝宝石坩埚来控制Tl2O的挥发,避免了陪烧靶的使用。XRD测试结果显示薄膜中心处为Tl-2223超导相,随着薄膜向边缘延伸,Tl-2223相逐渐分解为Tl_(2)Ba_(2)Ca_(1)Cu_(2)O_(8)(Tl-2212)相;薄膜反面也呈现相似的规律,但其Tl-2212相含量更高。SEM和AFM图像显示薄膜中心呈现层状结构,边缘呈现颗粒结构。测试结果表明该2英寸Tl-2223薄膜正反面的临界转变温度(T_(c))为105 K与101 K,临界电流密度(J_(c))平均都在1.0 MA/cm^(2)(77 K,0 T)左右。微波表面电阻(R_(s))为0.16 mΩ与2.28 mΩ(77 K,10 GHz),且随温度升高而变大,符合二流体模型。An improved two-step method for the preparation of double-sided Tl_(2)Ba_(2)Ca_(2)Cu_(3)O_(10)(Tl-2223)high-temperature superconducting films on 2-inch LaAlO_(3)(00l)substrates was proposed.The volatilization of Tl_(2)O can be controlled without the usage of additional Tl pellets by using a special sapphire crucible.XRD analysis verified the generation of the Tl-2223 phase in the middle of the obtained film.As the film extends towards the edge,the resultant Tl-2223 phase gradually decomposes into Tl_(2)Ba_(2)Ca_(1)Cu_(2)O_(8)(Tl-2212)phase.The downside of the film also showes a similar pattern,but its content of Tl-2212 phase is higher.SEM and AFM images show that the center of the film shows a layered structure and the edges present the particle structure.The measurement results of the 2-inch Tl-2223 film show that the critical temperature(T_(c))on the upside and downside of the film is 105 K and 101 K,the averaged critical current density(J_(c))on both sides is around 1.0 MA/cm^(2)(77 K,0 T).The microwave surface resistance(R_(s))on the upside and downside of the film is 0.16 mΩ and 2.28 mΩ(77 K,10 GHz)and increases with increasing temperature,which is consistent with the two-fluid model.

关 键 词：Tl-2223 高温超导薄膜 临界转变温度 临界电流密度 微波表面电阻 

分 类 号：TM26[一般工业技术—材料科学与工程]