Lee Sang Heon
Department of Electronic Engineering, Sunmoon University, Asan, Chungnam 31460, Korea.
J Nanosci Nanotechnol. 2021 Sep 1;21(9):4941-4943. doi: 10.1166/jnn.2021.19274.
In the present study, a YBa₂Cu₃O bulk superconductor added with 5~10 wt% Ag was fabricated employing Sm123 as a seed to produce a superconductive single crystal. Metallic silver was added to the single crystal of YBa₂Cu₃O to remove defects such as cracks and pores. Electromagnetic properties of the bulk superconductor at 77 K were analyzed based on relationships of magnetic levitation, trapped magnetic force, and critical current density. The critical current density of the superconductor at 77 K and 0 T was 3.53 × 10⁴ A/cm². Discontinuous points in the distribution of magnetic field lines were not observed, implying that these two specimens grew well as a single crystal without specific weak links. For the growth of a superconductive nano crystal employing slow cooling at temperature of formation of 123 phase, superconductive nano crystals were aligned in direction, the direction of peak current flow. The peak value of the trapped magnetic force of the YBa₂Cu₃O superconductor specimen was 3.23 kG. Using the FC method, peak forces of attraction and repulsion were 21.696 N and 70.168 N, respectively.
在本研究中，采用Sm123作为籽晶制备了添加5~10 wt%银的YBa₂Cu₃O块体超导体，以制备超导单晶。向YBa₂Cu₃O单晶中添加金属银以去除诸如裂纹和孔隙等缺陷。基于磁悬浮、俘获磁力和临界电流密度的关系，分析了该块体超导体在77 K时的电磁特性。该超导体在77 K和0 T时的临界电流密度为3.53×10⁴ A/cm²。未观察到磁力线分布中的不连续点，这意味着这两个样品作为单晶生长良好，没有特定的弱连接。对于在123相形成温度下采用缓慢冷却的超导纳米晶体的生长，超导纳米晶体沿峰值电流流动方向即 方向排列。YBa₂Cu₃O超导体样品的俘获磁力峰值为3.23 kG。使用FC方法，吸引和排斥的峰值力分别为21.696 N和70.168 N。
