Tl-2223超导薄膜的快速烧结新工艺研究  

New Rapid Sintering Process of Tl-2223 Superconducting Films

作　　者：金艳营 韩徐 蒋艳玲 周新红 马丽 谢清连 Jin Yanying;Han Xu;Jiang Yanling;Zhou Xinhong;Ma Li;Xie Qinglian(Key Laboratory of New Electrical Functional Materials in Guangxi Universities,School of Physics and Electronics,Nanning Normal University,Nanning 530299,China;School of Mechanical and Electrical Engineering,Guangxi Science&Technology Normal University,Laibin 546199,China)

机构地区：[1]南宁师范大学物理与电子学院,广西高校新型电功能材料重点实验室,广西南宁530299 [2]广西科技师范学院机械与电气工程学院,广西来宾546199

出　　处：《稀有金属》2024年第1期43-49,共7页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51962025);广西省自然科学基金项目(2018GXNSFAA138195)资助。

摘　　要：采用改进的快速升温烧结工艺在(001)取向的铝酸镧(LAO)衬底上制备Tl-2223超导薄膜,探索了在O_(2)环境下双温烧结过程中高温段烧结温度对超导薄膜晶体结构及超导性能的影响。X射线衍射(XRD)结果表明,烧结温度对Tl系超导薄膜的晶粒取向至关重要,采用合适的烧结温度可以制备出纯c轴取向生长的Tl-2223薄膜,且结晶质量良好;扫描电镜(SEM)图像显示超导薄膜表面平整,晶体结构致密,明显呈现出层状生长结构。907℃恒温2 min所制备的Tl-2223薄膜具有良好的超导性能,其临界转变温度(T_(c))可达115 K,临界电流密度(J_(c))约为1.6 mA·cm^(-2)(77 K,0 T)。该工艺简化了Tl-2223超导薄膜的制备过程,有效提高了实验效率。Tl-based high temperature superconducting materials have high critical transition temperature,high critical current density,and strong moisture resistance.It has a great potential application value in both of the strong and weak electric fields.In particular,Tl_2Ba_2Ca_2Cu_3O_(10) (Tl-2223),which belongs to the non-ideal typeⅡsuperconductors,has the highest transition temperature (128 K) in Tl-based superconducting family.It is a superconducting material suitable for practical application.The growth of high-quality Tl-2223 superconducting film is the basis for its application.At present,it isn't easy to prepare pure c-axis-oriented Tl-2223 films on the single crystal substrates.Because,in the traditional sintering method,the heating rate is too slow (2~10℃·min^(-1)),so the precursor film passes through the phase-formed temperature of other superconducting phases with a low critical transition temperature (such as Tl-2212 and Tl-1212) for a long time.When the temperature reaches the formation temperature of the Tl-2223 phase,other superconducting phases generated at low temperatures cannot be completely transformed or eliminated.Only the mixed-phase films can be obtained.Moreover,a low heating rate will lead to a long time of the constant temperature of the film,resulting in poor surface morphology.To solve these problems,the improved rapid heating-up sintering process (referred to as the double-temperature sintering process) was used to grow Tl-2223 films on (001) oriented lanthanum aluminate (LAO) substrates in this paper.The effect of the high-temperature section in the sintering process on the phase formation of superconducting films was explored.In this process,the crystallization of the precursor film included two constant temperature processes at different temperatures.First,the temperature was raised from room temperature to a certain temperature of 885~907℃at 35℃·s^(-1),and kept for 2 min.Then the temperature was lowered to 865℃at20℃·s^(-1) for 10 min and the superconducting sample was obta

关 键 词：快速升温烧结新工艺 c轴生长 Tl-2223超导薄膜 铝酸镧 

分 类 号：O484.1[理学—固体物理]