采用快速升温烧结方法生长Tl-1223超导薄膜的研究  

Growth of Tl-1223 superconducting thin films by rapidly heating-up sintering technology

作　　者：谢清连[1] 苏玲玲 蒋艳玲[1] 唐平英[1] 刘丽芹 岳宏卫[2] 陈名贤[1] 黄国华[1] Xie Qing-Lian;Su Ling-Ling;Jiang Yan-Ling;Tang Ping-Ying;Liu Li-Qin;Yue Hong-Wei;Chen Ming-Xian;Huang Guo-Hua(College of Physics and Electronic Engineering, C uangxi Teachers Education University, Nanning 530001, China;School of Information and Communication, Cuilin University of Electronic Technology, Guilin 541004, China)

机构地区：[1]广西师范学院物理与电子工程学院,南宁530001 [2]桂林电子科技大学信息与通信学院,桂林541004

出　　处：《物理学报》2018年第13期356-362,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:51062001;11264009);广西自然科学基金(批准号:2015jj DA10001);广西教育厅科研基金(批准号:KY2015ZD076);广西高校新型电功能材料重点实验室开放基金(批准号:DGN201702)资助的课题~~

摘　　要：报道了在铝酸镧(00l)衬底上生长Tl-1223超导薄膜的快速升温烧结方法以及铊(Tl)源陪烧靶的配比对Tl-1223薄膜晶体结构的影响.扫描电子显微镜观测表明,采用快速升温烧结方法生长的Tl-1223超导薄膜具有致密的晶体结构.X-射线衍射等测试表明,采用合适配比的陪烧靶在氩气环境下可以制备出纯c轴取向的Tl-1223超导薄膜,充氧退火后的薄膜具有较好的电学性能,其临界转变温度T_(c onset)达到116K,临界电流密度达到1.5MA/cm^2(77 K,0 T).实验结果表明,采用这一新的烧结方法制备Tl系超导薄膜具有升降温时间和恒温时间短、生产成本低等特点.Owing to high critical temperature（125 K） and high upper critical field, TlBa2Ca2Cu3O9（Tl-1223） superconductor is a kind of superconducting power transmission material working at liquefied natural gas temperature, and it has a great potential application value in the strong and weak electric field. In this work, the Tl-1223 superconducting films are fabricated by rapidly heating-up sintering technology（RHST） on（00 l） lanthanum aluminate substrates. The Tl-Ba-CaCu-O target is used as a sputtering source to deposit the precursor films by the radio-frequency magnetron sputtering technique. The Tl-contained pellets, named annealing targets, are fabricated by the solid-state reaction of stoichiometric quantities of Tl2O3, BaO2, CaO and CuO powders with an initial cation ratio of Tl：Ba：Ca：Cu = 0.4–1.8：2：2：3.The amorphous precursors together with the annealing target providing Tl source are sealed in a silver foil and annealed at 820？C for 5 min in argon atmosphere, then converted into Tl-1223 superconducting phase. The heating rates are set at 2.5？C/s from room temperature to 350？C, 5？C/s from 350？C to 650？C, and 35？C/s from 650？C to820？C, respectively. The prepared films are characterized by X-ray diffraction and scanning electron microscope. In the conventional low heating rate process, all of the precursor films sintered together with the annealing targets containing different Tl content are first converted into Tl-2212 superconducting phase. That is because the sample residence time in the phase transition temperature range of Tl-2212 is longer, while the phase-formed temperature of Tl-2212 is lower than that of Tl-1223. In the RHST, when the metal ion molar ratio of Tl to Ba in the annealing target is 1.8：2, the main phase of the film is（00 l）-oriented Tl-2212. In addition, the film also contains a small number of Tl-2223 grains. On reducing the ratio to 1：2, the film is composed of Tl-1212, Tl-2212, Tl-1223 and Tl-2223 grains. As the ratio decreases to 0.8�

关 键 词：Tl-1223超导薄膜 铝酸镧基片 快速升温烧结方法 

分 类 号：O484[理学—固体物理]