Critical Current of Low-Angle Grain Boundaries in High-Tc Superconductors

Alexander Kasatkin,Pavel Borisenko,Vadim Tsvetkovskii

doi:10.13189/ujpa.2013.010214

Abstract

Dependence of the critical current on the misorientation angle in high-temperature superconductor (001) tilt bicrystal is theoretically examined. We suppose that in the case of relatively small values of the bicrystal misorientation angle θ (θ ≤ 10÷15 0 ) the critical current is determined by depinning of vortices, which are locked by edge dislocations aligned along the bicrystal grain boundary. Dependence of the depinning critical current on the misorientation angle is calculated for this case and it reveals a good agreement with experimental data obtained on Y-Ba-Cu-O bicrystals with (001) tilt low-angle grain boundaries.

Highlights

High-temperature superconducting (HTS) materials produced on the base of ‘cuprate’ compounds (RE)-Ba-Cu-O (RE – is the rare-earth element: Y, Gd, Nd) are of great practical interest for electrical engineering and electronics [1]
The depinning critical current value is calculated for the case of periodic pinning potential Up(s), created by a linear row of parallel equidistant c-oriented edge dislocations, forming the low-angle [001] tilt grain boundary along the х – axis in HTS film or bicrystal
In the present work we examine dependence of the intergrain critical current density jc on the misorientation angle θ in HTS [001] tilt bicrystals

Summary

Introduction

High-temperature superconducting (HTS) materials produced on the base of ‘cuprate’ compounds (RE)-Ba-Cu-O (RE – is the rare-earth element: Y, Gd, Nd) are of great practical interest for electrical engineering and electronics [1]. In the framework of suggested model the main features of experimentally observed jc(θ ) dependence, such as plateau at low angles and exponential decrease at higher angle values, follow from the specific form of periodic vortex pinning potential, created by the equidistant edge dislocations row, which forms the [001] tilt low-angle grain boundary in HTS bicrystal.

Results

Conclusion