Improving Superconducting Performance of Fe(Se, Te) with In Situ Formed Grain-Boundary Strengthening and Flux Pinning Centers

2022 ◽  
Author(s):  
Jixing Liu ◽  
Botao Shao ◽  
Xueqian Liu ◽  
Meng Li ◽  
Lina Sang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Grain Boundary Strengthening

Three Dimensional Observation of Flux Pinning Centers in Dy-doped YBa2Cu3O7-x Coated Superconductors by STEM Tomography

2007 ◽  
Vol 1026 ◽  
Author(s):  
Volkan Ortalan ◽  
Miriam Herrera ◽  
David G. Morgan ◽  
Martin W. Rupich ◽  
Nigel D. Browning
Keyword(s):  
Particle Size ◽  
Grain Boundary ◽  
Flux Pinning ◽  
Three Dimensional ◽  
Scanning Transmission Electron Microscope ◽  
Coated Conductors ◽  
Chemical Doping ◽  
Pinning Centers ◽  
Scanning Transmission ◽  
Conductive Properties

AbstractThe spatial distribution of flux pinning centers in YBa2Cu3O7 (YBCO) coated conductors significantly affects the conductive properties. Nanoparticles acting as pinning centers can be intentionally introduced into the structure by chemical doping. In this study, a Dy-doped YBa2Cu3O7-x coated superconductor was investigated and the particle composition was found to be as (YsDy1-s)2Cu2O5 with s ∼0.6. A tomographic tilt series was acquired using a scanning transmission electron microscope (STEM) to determine the 3-D distribution of nanoparticles. In the investigated sample area, 71 particles were located with a particle size distribution ranging between 13 and 135 nm. The distribution uniformity and size of the particles appeared to be dependent on the grain boundary network structure. Large particles were observed to be located on grain boundaries indicating that fast grain boundary diffusion may determine the particle size.

The stability of dislocation networks under various oxygen-doping conditions in superconducting Bi2Sr2CaCu2Oy single crystals and their influence on the flux pinning properties

1994 ◽  
Vol 52 ◽  
pp. 802-803
Author(s):  
Y. Feng ◽  
X. Y. Cai ◽  
R. J. Kelley ◽  
D. C. Larbalestier
Keyword(s):  
Single Crystals ◽  
Oxygen Content ◽  
Basal Plane ◽  
Flux Pinning ◽  
Pinning Centers ◽  
Before And After ◽  
Anomalous Peak ◽  
Basal Plane Dislocation ◽  
The Stability ◽  
Further Development

The issue of strong flux pinning is crucial to the further development of high critical current density Bi-Sr-Ca-Cu-O (BSCCO) superconductors in conductor-like applications, yet the pinning mechanisms are still much debated. Anomalous peaks in the M-H (magnetization vs. magnetic field) loops are commonly observed in Bi2Sr2CaCu2Oy (Bi-2212) single crystals. Oxygen vacancies may be effective flux pinning centers in BSCCO, as has been found in YBCO. However, it has also been proposed that basal-plane dislocation networks also act as effective pinning centers. Yang et al. proposed that the characteristic scale of the basal-plane dislocation networksmay strongly depend on oxygen content and the anomalous peak in the M-H loop at ˜20-30K may be due tothe flux pinning of decoupled two-dimensional pancake vortices by the dislocation networks. In light of this, we have performed an insitu observation on the dislocation networks precisely at the same region before and after annealing in air, vacuumand oxygen, in order to verify whether the dislocation networks change with varying oxygen content Inall cases, we have not found any noticeable changes in dislocation structure, regardless of the drastic changes in Tc and the anomalous magnetization. Therefore, it does not appear that the anomalous peak in the M-H loops is controlled by the basal-plane dislocation networks.

In situ observation of multiple parallel (1 1 1) twin boundary formation from step-like grain boundary during Si solidification

2020 ◽  
Vol 13 (10) ◽  
pp. 105501
Author(s):  
Kuan-Kan Hu ◽  
Kensaku Maeda ◽  
Keiji Shiga ◽  
Haruhiko Morito ◽  
Kozo Fujiwara
Keyword(s):  
Grain Boundary ◽  
Twin Boundary ◽  
In Situ Observation ◽  
Boundary Formation

scholarly journals Time-Response-Histogram-Based Feature of Magnetic Barkhausen Noise for Material Characterization Considering Influences of Grain and Grain Boundary under In Situ Tensile Test

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2350
Author(s):  
Jia Liu ◽  
Guiyun Tian ◽  
Bin Gao ◽  
Kun Zeng ◽  
Yongbing Xu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Tensile Stress ◽  
Material Properties ◽  
Ferromagnetic Material ◽  
Silicon Steel ◽  
Time Response ◽  
Barkhausen Noise ◽  
Time Interval ◽  
Magnetic Barkhausen Noise

Stress is the crucial factor of ferromagnetic material failure origin. However, the nondestructive test methods to analyze the ferromagnetic material properties’ inhomogeneity on the microscopic scale with stress have not been obtained so far. In this study, magnetic Barkhausen noise (MBN) signals on different silicon steel sheet locations under in situ tensile tests were detected by a high-spatial-resolution magnetic probe. The domain-wall (DW) motion, grain, and grain boundary were detected using a magneto-optical Kerr (MOKE) image. The time characteristic of DW motion and MBN signals on different locations was varied during elastic deformation. Therefore, a time-response histogram is proposed in this work to show different DW motions inside the grain and around the grain boundary under low tensile stress. In order to separate the variation of magnetic properties affected by the grain and grain boundary under low tensile stress corresponding to MBN excitation, time-division was carried out to extract the root-mean-square (RMS), mean, and peak in the optimized time interval. The time-response histogram of MBN evaluated the silicon steel sheet’s inhomogeneous material properties, and provided a theoretical and experimental reference for ferromagnetic material properties under stress.

Flux Pinning Characteristics of Artificial Pinning Centers With Different Dimension

2009 ◽  
Vol 19 (3) ◽  
pp. 3248-3253 ◽  
Author(s):  
K. Matsumoto ◽  
P. Mele ◽  
A. Ichinose ◽  
M. Mukaida ◽  
Y. Yoshida ◽  
...  
Keyword(s):  
Flux Pinning ◽  
Pinning Centers ◽  
Artificial Pinning Centers

Influence of Al/Cu content on grain boundary diffusion in Nd-Fe-B magnet via in-situ observation

2019 ◽  
Vol 37 (4) ◽  
pp. 398-403 ◽  
Author(s):  
Xinghua Cheng ◽  
Jian Li ◽  
Lei Zhou ◽  
Tao Liu ◽  
Xiaojun Yu ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Boundary Diffusion ◽  
Grain Boundary Diffusion ◽  
In Situ Observation ◽  
Cu Content
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