YBa2Cu3O7−x (YBCO) nanocomposites for wire applications need to operate in a broad range of frequencies, ranging from dc in magnets to Gz in cavities and screenings of future particle accelerators. We have investigated the in-field and angular vortex pinning performance in dc and at 50 GHz of two types of nanocomposites, pulsed laser deposition (PLD) YBCO with Ba2YNbO6 (BYNTO) nanorods and chemical solution deposited (CSD) YBCO with BaHfO3 (BHO) nanoparticles (NPs), and the pristine counterpart films, grown on top of single-crystalline substrates. Transport measurements performed up to 9 T between 5-77 K show that CSD nanocomposites exhibit a smooth field decay and increased single-to-collective crossover field H* compared to pristine samples, associated to the enhanced isotropic pinning contribution induced by the NPs, while PLD films exhibit unchanged H* and superior critical current densities up to higher irreversibility fields, associated to the anisotropic contribution introduced by the rods. Microwave in-field measurements of the pinning constant kp revealed CSD NCs exhibit a qualitatively similar, but smoother kp(H) than pristine samples, whereas for PLD samples, an increasing kp(H) dependence is observed as a result of the increased relevance of the stiffness of the fluxons pinned by nanorods.

中文翻译：

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具有纳米棒和纳米粒子的 YBa2Cu3O7-x 薄膜在直流和微波频率下的涡旋钉扎特性

用于导线应用的 YBa2Cu3O7-x (YBCO) 纳米复合材料需要在很宽的频率范围内运行，从磁铁中的直流到空腔中的 Gz 以及未来粒子加速器的筛选。我们研究了直流和 50 GHz 两种类型纳米复合材料的场内和角涡旋钉扎性能，脉冲激光沉积 (PLD) YBCO 与 Ba2YNbO6 (BYNTO) 纳米棒和化学溶液沉积 (CSD) YBCO 与 BaHfO3 (BHO)纳米颗粒 (NPs) 和原始的对应薄膜，生长在单晶基板上。在 5-77 K 之间进行高达 9 T 的传输测量表明，与原始样品相比，CSD 纳米复合材料表现出平滑的场衰减和增加的单到集体交叉场 H*，这与由 NP 引起的增强的各向同性钉扎贡献相关，而 PLD 薄膜表现出不变的 H* 和优异的临界电流密度，直至更高的不可逆场，这与棒引入的各向异性贡献有关。钉扎常数 kp 的微波现场测量显示 CSD NC 表现出质量相似但比原始样品更平滑的 kp(H)，而对于 PLD 样品，观察到增加的 kp(H) 依赖性是由于由纳米棒固定的磁通子的刚度。