Large Enhancement of the Critical Curent Density Due to Vortex Matching at Periodic Facet Structure in YBa[d2]Cu[d3]O[d7-[delta]] Bicrystals

Published

January 12, 1998

Author(s)

X Y. Cai, A Gurevich, I F. Tsu, Debra Kaiser, S E. Babcock, D C. Larbalestier

Abstract

We observe pronounced peaks in the critical current density (J[db](B) vs. applied magnetic field B in YBa[d2]Cu[d3]O[d7-delta] bicrystals well above the lower critical field. These peaks correspond to the fields for which the spacing between intragrain vortices is commensurate with the wave length of the periodic grain boundary facet structure observed in the same bicrystals. The peaks were observed on a group of grain boundaries that were isolated from four bulk [001]-tilt bicrystals with misorientation angles around 15 , which lie in the transition region from strong to weak coupling. The matching effect provides direct evidence that faceting strongly modulates the coupling strength of grain boundaries and can substantially increase J[db](B) in high magnetic fields. Periodic modulation of the intergrain coupling by the strain fields observed at the facet junctions by transmission electron microscopy is proposed as the origin of the J[dc](B) enhancement.

Citation

Physical Review B (Condensed Matter and Materials Physics)

Volume

57

Issue

1

Pub Type

Journals

Keywords

critical current density, facet structure, grain boundaries, high temperature superconductor, vortex, YBa[d2]Cu[d3]O[d7-x]

Citation

Cai, X. , Gurevich, A. , Tsu, I. , Kaiser, D. , Babcock, S. and Larbalestier, D. (1998), Large Enhancement of the Critical Curent Density Due to Vortex Matching at Periodic Facet Structure in YBa[d2]Cu[d3]O[d7-[delta]] Bicrystals, Physical Review B (Condensed Matter and Materials Physics) (Accessed April 25, 2024)