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通过脉冲激光沉积技术(PLD),在氧化物缓冲层合金基底上外延生长一系列具有相同厚度,不同BaHfO3插层数(N=0、1、2、3)的YBa_2Cu_3O_(7-δ)/BaHfO_3/YBa_2Cu_3O_(7-δ)复合多层膜.X光衍射分析表明:所有样品都是c轴取向,随着层数的增加,薄膜的面内和面外织构有一定的退化.拉曼光谱图也可以看出除了N=3的样品有微弱的a轴峰,其它样品都只有c轴峰.通过扫描电镜观察发现,BaHfO_3插层的引入没有对YBa_2Cu_3O_(7-δ)超导薄膜表面产生明显的影响,薄膜表面光滑无裂痕.通过原子力显微镜发现YBa_2Cu_3O_(7-δ)超导薄膜的粗糙度在引入单层BaHfO3插层时最大,之后随着插层数的增加而减小.感应法测试表明,BaHfO3插层数为N=1时,YBa_2Cu_3O_(7-δ)超导薄膜的临界电流密度Jc(77K,自场)达到2.86 MA/cm2.在场临界电流表明,引入较少BaHfO_3插层(N=1、2)表现相对好的磁场依赖关系.
A series of YBa_2Cu_3O_ (7-δ) / BaHfO_3 with the same thickness and different number of BaHfO 3 intercalation (N = 0, 1, 2, 3) were epitaxially grown on the oxide buffer alloy substrate by pulsed laser deposition (PLD) / YBa_2Cu_3O_ (7-δ) composite multilayer films.X-ray diffraction analysis showed that all the samples were c-axis oriented, with the number of layers increasing, the in-plane and out-of-plane texture of the films degenerated.Raman spectra It can also be seen from the figure that there is a weak a-axis peak in all samples except N = 3 and only c-axis peaks in other samples. The scanning electron microscopy showed that the introduction of BaHfO_3 intercalation did not produce the surface of YBa_2Cu_3O_ (7-δ) The roughness of YBa_2Cu_3O_ (7-δ) superconducting thin films was the largest when intercalated into BaHfO 3 monolayer, and then decreased with the increase of intercalation number. The results show that the critical current density Jc (77K, self-field) of YBa_2Cu_3O_ (7-δ) superconducting thin film reaches 2.86 MA / cm 2 when the intercalation number of BaHfO 3 is N = 1. The presence of the critical current shows that less BaHfO_3 intercalation (N = 1, 2) exhibit relatively good magnetic field dependence.