An Exponential Model for Critical Current Density Through a Low-Angle Grain Boundary in a High-T c Superconductor
An analytical investigation is presented to display the distribution of critical current flow through a low-angle grain boundary in a high-T c superconductor such as YBCO or Bi-2212 film. When a superconductor is subjected to a transport current or a magnetic field, the fluxoids are redistributed between the dislocations which comprise a low-angle grain boundary. A model considering the elastic interaction between a flux line and an edge dislocation is developed in this paper. Results of our model are consistent with those of the classic exponential model, while for high-angle grain boundaries with the misorientation angles 𝜃 > 4∘, this model is invalid. It is helpful by using our model to understand the mechanisms of the effect of low-angle grain boundaries on critical current density.
KeywordsCritical current density Grain boundary Dislocation
This research was partially funded by the Natural Science Foundation of China (Nos. 11402073 and 11372096), the China Postdoctoral Science Foundation (No. 2013M531260), the Fund of Natural Science Foundation of Jiangsu Province (No. BK20130824), and the Program for Research Fund for the Doctoral Program of Higher Education of China.
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