YBa_2Cu_3O_(7-δ)纳米点的制备及其对超导磁通钉扎性能的影响

Fabrication of YBa_2Cu_3O_(7-δ) Nanodots and Its Effect on Flux Pinning of Superconductor

为了提高YBa_2Cu_3O_(7-δ)(YBCO)超导薄膜在磁场作用下的载流能力,首先使用YBCO前驱体溶液在LaAlO_3单晶基板上制备了钉扎中心。通过改变YBCO前驱体溶液的浓度,改变基板上YBCO钉扎中心的尺寸和密度。然后在YBCO纳米点上表面外延生长YBCO薄膜。分析了YBCO在纳米点上生长膜层的取向、织构,研究了YBCO纳米点的磁通定扎效果。结果表明:使用0.1 mol/L的低浓度YBCO前驱体溶液可以获得细小的,尺寸约为30 nm且分布均匀的YBCO纳米点;在其上沉积的YBCO薄膜具有良好的织构,其磁通钉扎效果最明显,表现出了良好的抗磁场效应。随着YBCO前驱体浓度的增加,钉扎中心的尺寸逐渐增大,对YBCO厚膜的磁通钉扎效果逐渐衰减。不同浓度YBCO前驱体制备的纳米点对YBCO厚膜的外延生长没有影响。

In order to increase the current capacity of YBa2Cu307-δ （YBCO） superconductor in a magnetic field, the pinning central on the LaAlO3 crystal substrate was prepared with YBCO precursor solution, and the size and density were adjusted at various concentrations of YBCO precursor solution. The YBCO films on the YBCO nanodots surface were epitaxially grown. The growth orientation and texture of YBCO film were analyzed, and the magnetization behavior of YBCO film was investigated. The results show that the tiny and uniform YBCO nanodots with the size of 30 nm can be synthesized at the YBCO precursor solution of 0.1 mol/L concentration. A great thickness YBCO film deposited on these nanodots has a good texture, and the flux pinning effect increases, showing a good anti-magnetic field effect. The size of flux pinning central increases and the effect of flux pinning decreases with the increase of YBCO precursor concentration. The nanodots fabricated at different concentrations of YBCO precursor have no effect on the epitaxial growth of thick YBCO film.