Jc enhancement in Tl2Ba2CaCu2Ox thin films by introduction of CeO2 nanodots on substrates
Jc enhancement in Tl2Ba2CaCu2Ox thin films by introduction of CeO2 nanodots on substrates
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DOI：
10.1088/0953-2048/24/6/065021
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发表时间：
2011-06
影响因子：
3.6
通讯作者：
L. Ji;Z. Wang;Q. Xie;Xinjie Zhao;M. He;W. Li;F. Song;L. Fang;S. Yan
中科院分区：
文献类型：
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作者：
L. Ji;Z. Wang;Q. Xie;Xinjie Zhao;M. He;W. Li;F. Song;L. Fang;S. Yan
采用常规直流溅射和后退火工艺制备了Tl_2Ba_2CaCu_2Ox（Tl-2212）薄膜。为了利用人为缺陷来提高磁通钉扎强度，在生长Tl-2212薄膜之前，通过射频（rf）磁控溅射从铈金属靶在LaAlO 3（001）衬底上沉积纳米尺寸的CeO 2点。在引入纳米点的衬底上的Tl-2212薄膜的临界电流密度Jc（77 K）在自电场下达到6 × 106 A cm-2，这是在正常衬底上的临界电流密度的1.7倍。在磁场作用下，在含有人工缺陷的衬底上生长的Tl-2212薄膜的Jc增强更为明显。在0.5 T直流磁场下，观察到3.5 × 104 A cm-2的Jc（77 K），这是正常衬底上的约13倍。
Tl2Ba2CaCu2Ox (Tl-2212) thin films with enhanced transport critical current densities Jc were fabricated by using conventional dc sputtering and a post-annealing process. In order to employ artificial defects to improve the flux pinning strength, nano-sized CeO2 dots were deposited on the LaAlO3(001) substrates by radiofrequency (rf) magnetron sputtering from a cerium metal target prior to the growth of Tl-2212 films. The critical current density Jc (77 K) of the Tl-2212 thin film on the nanodot-introduced substrate reaches 6 × 106 A cm − 2 at self-field, which is 1.7 times larger than that on the normal substrate. The enhancement of the Jc in Tl-2212 film grown on the substrate with artificial defects is more obvious in magnetic fields. At 0.5 T dc magnetic field, a Jc (77 K) of 3.5 × 104 A cm − 2 is observed, which is about 13 times larger than that on the normal substrate.