Abstract Superconducting composite products of type YBa2Cu3O7−d (noted Y-123) added with different contents (x wt.%) of tungsten oxide nanoparticles (WO3 NPs), x = 0.0–1.0 wt%, were produced via the standard solid-state reaction technique. Samples were investigated by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrical resistivity measurements. XRD examination showed that the Y-123 orthorhombic structure is not altered by WO3 NPs additions. SEM observations indicated a reduction in the grains size with the increase of nanoparticles content. The investigation of the excess conductivity of different prepared composites was analyzed using Aslamazov-Larkin (AL) model. The investigated samples comprised of five distinct fluctuation regimes, namely short-wave (SWF), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and critical (CR) fluctuations regimes. The coherence length along c-axis at zero-temperature ( ξ c ( 0 ) ), lower and upper critical magnetic fields ( B c 1 and B c 2 ), critical current density ( J c ) and numerous other superconducting parameters were estimated with respect to WO3 NPs content. Compared to undoped Y-123 sample, it was found that an amount of x = 0.05 wt% of WO3 NPs is appropriate to improve the physical performances of Y-123, whereas with further increasing x, these performances were weakened.

中文翻译：

---

YBa2Cu3O7−d/(WO3 NPs)x复合材料的尺寸和超导参数从超导分析推导出

摘要 YBa2Cu3O7-d 型超导复合产品（记为 Y-123）添加了不同含量（x wt.%）的氧化钨纳米颗粒（WO3 NPs），x = 0.0–1.0 wt%，通过标准固态制备反应技术。通过 X 射线衍射 (XRD)、扫描电子显微镜 (SEM) 和电阻率测量来研究样品。XRD 检查表明 Y-123 正交结构不会因 WO3 NPs 添加而改变。SEM观察表明随着纳米颗粒含量的增加晶粒尺寸减小。使用 Aslamazov-Larkin (AL) 模型分析了不同制备复合材料的过量电导率的研究。研究的样本由五种不同的波动状态组成，即短波 (SWF)、一维 (1D)、二维 (2D)、三维 (3D) 和临界 (CR) 波动机制。在零温度 ( ξ c ( 0 ) )、上下临界磁场 ( B c 1 和 B c 2 )、临界电流密度 ( J c ) 和许多其他超导参数下，沿 c 轴的相干长度估计为关于 WO3 NPs 的含量。与未掺杂的 Y-123 样品相比，发现 x = 0.05 wt% 的 WO3 NPs 的量适合提高 Y-123 的物理性能，而随着 x 的进一步增加，这些性能减弱。