Flux pinning enhancement in YBa2Cu3O7−x films with BaSnO3 nanoparticles
Flux pinning enhancement in YBa2Cu3O7−x films with BaSnO3 nanoparticles
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DOI：
10.1088/0953-2048/19/10/l01
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发表时间：
2006-10
影响因子：
3.6
通讯作者：
C. Varanasi;P. Barnes;J. Burke;L. Brunke;Iman Maartense;T. Haugan;E. Stinzianni;Kathleen Dunn
中科院分区：
文献类型：
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作者：
C. Varanasi;P. Barnes;J. Burke;L. Brunke;Iman Maartense;T. Haugan;E. Stinzianni;Kathleen Dunn
将纳米BaSnO_3掺杂到LaAl_3衬底上的YBa2Cu3O7-−_x(YBCO)薄膜中，以增强磁通钉扎作用。与常规的YBCO薄膜相比，在77K、6T下的高场磁化强度Jc提高了一个数量级以上。在77K时不可逆场(Hirr)增加到8.5T，在65K时增加到13.4T。场内输运电流测量证实了高场下的数量级改善。1T时JC数据的角度依赖关系表明，这比c轴相关缺陷的存在要高1.3倍。透射电子显微镜研究表明，BaSnO310 nm尺寸的∼析出物及其周围的应变场密度很大，分布均匀。使用双扇区脉冲激光沉积靶来制备薄膜，从而消除了靶制备阶段BaSnO_3和YBCO之间的反应，但可能允许BaSnO_3局部反应并产生充当钉扎中心的缺陷。
Nanoparticles of BaSnO3 were incorporated into YBa2Cu3O7−x (YBCO) films on LaAlO3 substrates for magnetic flux pinning enhancements. More than an order of magnitude improvement in the high field magnetization Jc at 6 T at 77 K was observed as compared to regular YBCO films. The irreversibility field (Hirr) was increased to 8.5 T at 77 K and to 13.4 T at 65 K. The in-field transport current measurements confirmed an order of magnitude improvement in high fields. The angular dependence of the Jc data at 1 T showed that is 1.3 times higher than indicating the presence of c-axis correlated defects. Transmission electron microscopy studies revealed the presence of a large density of uniformly distributed ∼10 nm sized BaSnO3 precipitates and strain fields around them. A dual sector pulsed laser deposition target is used to produce the films, thus eliminating reactions between BaSnO3 and YBCO during the target preparation stage, but may allow the BaSnO3 to react locally and create defects that act as pinning centres.