Epitaxial superconducting GdBa2Cu3O7-δ/Gd2O3 nanocomposite thin films from advanced low-fluorine solutions
Epitaxial superconducting GdBa2Cu3O7-δ/Gd2O3 nanocomposite thin films from advanced low-fluorine solutions
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DOI：
10.1088/1361-6668/aa8ffe
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发表时间：
2017-12-01
影响因子：
3.6
通讯作者：
Obradors, Xavier
中科院分区：
文献类型：
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作者：
Cayado, Pablo;Mundet, Bernat;Obradors, Xavier
我们采用CSD方法合成了GdBCO和GdBCO- gd2o3纳米复合材料250 ~ 300 nm薄膜。为此，我们设计了一种新的低氟溶液，以前从未用于GdBCO薄膜的合成，使我们能够减少80%的HF释放，并提高热解过程的可重复性。这些薄膜的生长需要设计一种新的加热过程，我们称之为“闪热”，其中加热速度非常快（类似于600℃min(-1)）。原始GdBCO薄膜的结构和超导性能优异，GdBCO晶粒呈（00 1）外延取向，T-c值达到92.8 K，比标准YBCO薄膜提高了1 K以上。晶粒内部的J(c)(G)也呈现出显著的数值：J(c)(G)（5K）近似于40 MA cm(-2)， J(c)(G)（77 K）近似于3.3 MA cm（-2）。最后，GdBCO-Gd2O3纳米复合膜在Gd2O3含量为20%的情况下，与GdBCO原始膜相比，具有更好的超导性能和钉住性能。
We have employed the CSD method to synthesize GdBCO and GdBCO-Gd2O3 nanocomposite 250-300 nm thin films. For this we have designed a new low-fluorine solution never used before in the synthesis of GdBCO thin films that allows us to reduce the HF release by 80% and increase the reproducibility of the pyrolysis process. The growth of these thin films required a new thermal process to be designed, which we refer to as 'flash-heating', where the heating rate is extremely fast (similar to 600 degrees C min(-1)). The structure and the superconducting properties of the pristine GdBCO films are excellent, showing a (00 1) epitaxial orientation of the GdBCO grains and T-c values that reach 92.8 K, which means an enhancement of more than 1 K with respect to standard YBCO films. The calculated J(c) inside the grains (J(c)(G)) also presents remarkable values: J(c)(G)(5K) similar to 40 MA cm(-2) and J(c)(G)(77 K) similar to 3.3 MA cm(-2). Finally, the GdBCO-Gd2O3 nanocomposites films, with a 20% mol of Gd2O3, exhibit superior superconducting properties and pinning performances with respect to GdBCO pristine films.