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Title: ac susceptibility and grain-boundary pinning strengths in YBa sub 2 Cu sub 3 O sub 7 minus. delta. and YBa sub 2 Cu sub 2. 985 Ag sub 0. 015 O sub 7 minus. delta

Abstract

Estimation of the relative flux-pinning strengths of the matrix and the grain boundaries in polycrystalline oxide superconductors contributes to the understanding of their superconducting properties. Such understanding is further enhanced if measurements can be compared with those from materials with lattice substitution and doped grain boundaries. The ac susceptibilities of polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} and YBa{sub 2}Cu{sub 2.985}Ag{sub 0.015}O{sub 7{minus}{delta}} were measured as functions of temperature, ac-magnetic-field strength, and frequency. The presence of two loss peaks in the imaginary part of the susceptibility, {chi}{prime}{prime}, was confirmed by comparison of ac and dc measurements obtained on materials with different microstructures. One peak in {chi}{prime}{prime} was found to be associated with the matrix transition and the other, at lower temperatures, with weak-link behavior at grain boundaries. The model by K.-H. Mueller for the field dependence of the peaks was used to estimate and compare the pinning-force densities in the matrix and at weak links for both pure and Ag-substituted YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. In the temperature range (75--90 K) and field range (1--10 Oe, rms) studied, similar pinning forces, 6{times}10{sup 8} T A m{sup {minus}2}, for the matrix of the two materials were found, but the pinning-force densities at the weakmore » links were higher for the Ag-substituted material by a factor of 1.5, i.e., 10{sup 4} T A m{sup {minus}2} for YBa{sub 2}Cu{sub 2.985}Ag{sub 0.015}O{sub 7{minus}{delta}} as compared to 6{times}10{sup 3} T A m{sup {minus}2} for YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}.« less

Authors:
; ; ; ;  [1]
  1. IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 (USA)
Publication Date:
OSTI Identifier:
6883828
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter; (USA)
Additional Journal Information:
Journal Volume: 41:13; Journal ID: ISSN 0163-1829
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; BARIUM OXIDES; GRAIN BOUNDARIES; MAGNETIC SUSCEPTIBILITY; COPPER OXIDES; YTTRIUM OXIDES; FREQUENCY DEPENDENCE; MAGNETIC FLUX; SILVER ADDITIONS; TEMPERATURE DEPENDENCE; ALKALINE EARTH METAL COMPOUNDS; ALLOYS; BARIUM COMPOUNDS; CHALCOGENIDES; COPPER COMPOUNDS; CRYSTAL STRUCTURE; MAGNETIC PROPERTIES; MICROSTRUCTURE; OXIDES; OXYGEN COMPOUNDS; PHYSICAL PROPERTIES; SILVER ALLOYS; TRANSITION ELEMENT COMPOUNDS; YTTRIUM COMPOUNDS; 360204* - Ceramics, Cermets, & Refractories- Physical Properties

Citation Formats

Shinde, S L, Morrill, J, Goland, D, Chance, D A, and McGuire, T. ac susceptibility and grain-boundary pinning strengths in YBa sub 2 Cu sub 3 O sub 7 minus. delta. and YBa sub 2 Cu sub 2. 985 Ag sub 0. 015 O sub 7 minus. delta. United States: N. p., 1990. Web. doi:10.1103/PhysRevB.41.8838.
Shinde, S L, Morrill, J, Goland, D, Chance, D A, & McGuire, T. ac susceptibility and grain-boundary pinning strengths in YBa sub 2 Cu sub 3 O sub 7 minus. delta. and YBa sub 2 Cu sub 2. 985 Ag sub 0. 015 O sub 7 minus. delta. United States. doi:10.1103/PhysRevB.41.8838.
Shinde, S L, Morrill, J, Goland, D, Chance, D A, and McGuire, T. Tue . "ac susceptibility and grain-boundary pinning strengths in YBa sub 2 Cu sub 3 O sub 7 minus. delta. and YBa sub 2 Cu sub 2. 985 Ag sub 0. 015 O sub 7 minus. delta". United States. doi:10.1103/PhysRevB.41.8838.
@article{osti_6883828,
title = {ac susceptibility and grain-boundary pinning strengths in YBa sub 2 Cu sub 3 O sub 7 minus. delta. and YBa sub 2 Cu sub 2. 985 Ag sub 0. 015 O sub 7 minus. delta},
author = {Shinde, S L and Morrill, J and Goland, D and Chance, D A and McGuire, T},
abstractNote = {Estimation of the relative flux-pinning strengths of the matrix and the grain boundaries in polycrystalline oxide superconductors contributes to the understanding of their superconducting properties. Such understanding is further enhanced if measurements can be compared with those from materials with lattice substitution and doped grain boundaries. The ac susceptibilities of polycrystalline YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} and YBa{sub 2}Cu{sub 2.985}Ag{sub 0.015}O{sub 7{minus}{delta}} were measured as functions of temperature, ac-magnetic-field strength, and frequency. The presence of two loss peaks in the imaginary part of the susceptibility, {chi}{prime}{prime}, was confirmed by comparison of ac and dc measurements obtained on materials with different microstructures. One peak in {chi}{prime}{prime} was found to be associated with the matrix transition and the other, at lower temperatures, with weak-link behavior at grain boundaries. The model by K.-H. Mueller for the field dependence of the peaks was used to estimate and compare the pinning-force densities in the matrix and at weak links for both pure and Ag-substituted YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. In the temperature range (75--90 K) and field range (1--10 Oe, rms) studied, similar pinning forces, 6{times}10{sup 8} T A m{sup {minus}2}, for the matrix of the two materials were found, but the pinning-force densities at the weak links were higher for the Ag-substituted material by a factor of 1.5, i.e., 10{sup 4} T A m{sup {minus}2} for YBa{sub 2}Cu{sub 2.985}Ag{sub 0.015}O{sub 7{minus}{delta}} as compared to 6{times}10{sup 3} T A m{sup {minus}2} for YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}.},
doi = {10.1103/PhysRevB.41.8838},
journal = {Physical Review, B: Condensed Matter; (USA)},
issn = {0163-1829},
number = ,
volume = 41:13,
place = {United States},
year = {1990},
month = {5}
}