In this study, we investigate metallic nanocomposites to elucidate the properties of nanostructured conventional superconductors. Liquid tin, indium, and mercury are loaded into opal matrices by high pressure up to 10 kbar. The opal templates preserve the 3D dendritic morphology of confined superconducting metals to model a dendritic second phase with particular grain shape in bulk superconductors observed by a DualBeam microscope. We carry out measurements of the dc and ac magnetizations to study the superconducting phase diagrams, vortex dynamics, and impact of grain morphology in the opal composites. Besides, we apply the small-angle neutron scattering (SANS) to deny a regular vortex structure. The phase diagrams reveal an enhanced upper critical field H_c2(0) and curvature crossover in the upper critical field line. We also calculate the vortex activation barriers U_a and observe a transformation in the vortex system. According to the field dependence of U_a, the vortex structure transformation highly correlates with the curvature crossover in the upper critical field line. Our observations suggest that the similarity in the normalized phase diagrams and field dependences of U_a in the three nanocomposites is owing to their particular morphology of confinement.

在这项研究中，我们研究了金属纳米复合材料，以阐明纳米结构常规超导体的特性。液态锡，铟和汞在高达10 kbar的高压下被加载到蛋白石基质中。蛋白石模板保留受限超导金属的3D树枝状形态，以模拟通过DualBeam显微镜观察到的散装超导体中具有特定晶粒形状的树枝状第二相。我们对直流和交流磁化强度进行测量，以研究蛋白石复合材料中的超导相图，涡旋动力学以及晶粒形态的影响。此外，我们应用小角度中子散射（SANS）来否认规则的涡旋结构。相图揭示了增强的上临界场H _{c 2}（0）和上临界场线中的曲率交叉。我们还计算了涡旋激活势垒U _a并观察了涡旋系统中的变换。根据U _a的场相关性，涡旋结构变换与上临界场线中的曲率交叉高度相关。我们的观察结果表明，在三种纳米复合物中归一化相图的相似性和U _a在电场中的相依性是由于它们特定的限制形态。