Improving Superconductivity, Microstructure, and Mechanical Properties by Substituting Different Ionic Pb Elements to Bi and Ca Elements in Bi-2223 Superconductors
Improving Superconductivity, Microstructure, and Mechanical Properties by Substituting Different Ionic Pb Elements to Bi and Ca Elements in Bi-2223 Superconductors
复制标题
Bi-2223超导体中不同离子Pb元素替代Bi和Ca元素改善超导性、微观结构和机械性能
DOI：
10.1007/s10948-022-06209-5
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发表时间：
2022
影响因子：
1.8
通讯作者：
A. Üzümcü
中科院分区：
文献类型：
--
作者：
N. K. Saritekin;A. Üzümcü
详细研究了在不同的铣削时间间隔（0.5 h≤x≤8 h）下制备的块体bi1.8 pb0.2 sr2.0 ca1.8 pb0.2 cu30材料的显微组织、力学和超导特性的变化。采用x射线粉末衍射仪（XRD）和维氏显微硬度仪（Hv）对BSCCO样品进行了表征。所有的测量和计算结果都表明，在3小时的磨铣时间内，对技术、工业和工程应用负责的特性得到了显着改善，超过3小时则趋于恶化。特性的增强一般与(Bi, Pb)-2223的欠掺杂水平随着磨矿时间的延长而过渡到最佳掺杂水平有关，这一事件证明了有足够的Pb纳米颗粒穿透晶体结构。另一方面，cu - o2连续堆叠层中存在孔隙、无序、缺陷和局部化问题是超导性能受到抑制的部分原因。除上述原因外，结晶度下降、平均晶粒尺寸减小、cu - o2层中可移动孔浓度降低是造成cu - o2层结晶度下降的主要原因。同样，Pb夹杂物增加了(Bi, Pb)-2223超导体系中的人工随机位错和晶界弱环节。维氏显微硬度测量表明，(Bi, Pb)-2223块体超导试样表现出典型的压痕尺寸行为，这取决于系统中弹性和塑性变形的存在。采用Meyer定律、PRS模型、MPRS模型、弹塑性变形模型和Hays-Kendall方法对硬度测量结果进行了分析。因此，Hays-Kendall方法被认为是描述样品力学性能的最成功的模型。
In this detailed study, the changes of microstructural, mechanical, and superconducting features of bulk Bi1.8Pb0.2Sr2.0Ca1.8Pb0.2Cu3Oymaterials prepared at different milling time intervals (0.5 h ≤x≤ 8 h) were investigated in the most precise manner. The measurements of X-ray powder diffraction (XRD) and Vickers microhardness (Hv) were designed to scrutinize the bulk BSCCO samples. All the results of the measurements and calculations show that the characteristics responsible for the applications of the technology, industry, and engineering are significantly improved up to the 3 h milling time beyond that they tend to deteriorate. The enhancement of the characters is generally related to the transition from underdoped level of the (Bi, Pb)-2223 to the optimum level with the milling duration and this event approves that sufficient Pb nanoparticles penetrate the crystal structure. On the other hand, some of the reasons for the suppression in the superconducting properties are the presence of the porosity, disorder, defects, and the localization problem in the Cu-O2consecutively stacked layers. In addition to those mentioned above, the other reasons are degradation in the crystallinity, reduction in the average crystallite size, and decrease in mobile hole concentration in the Cu-O2layers. Similarly, the Pb inclusion rises the artificial random dislocations and grain boundary weak-links in the (Bi, Pb)-2223 superconducting system. Vickers microhardness measurements show that (Bi, Pb)-2223 bulk superconducting specimens exhibit typical indentation size behavior depending on the presence of both elastic and plastic deformations in the system. The results obtained from the hardness measurements have been analyzed by using Meyer law, PRS model, MPRS model, elastic–plastic deformation model, and Hays-Kendall approach. As a result, the Hays-Kendall approach was identified as the most successful model in describing the mechanical properties of the samples.