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Title: Influence of oxygen stoichiometry on the irreversible magnetization and flux creep in {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals

Abstract

The influence of the oxygen stoichiometry on magnetization and relaxation of {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals was studied for 0{le}{delta}{le}0.55. The field dependences of the shielding currents {ital j}{sub {ital s}}({ital H}) and flux creep rates {ital S}({ital H}) were analyzed. Three different kinds of {ital j}{sub {ital s}}({ital H}) and {ital S}({ital H}) behavior can be seen in highly oxygenated samples ({delta}{lt}0.1). At high temperatures, {ital j}{sub {ital s}}({ital H}) shows a common fishtail peak, which is present for all oxygen contents. The field position and height of the {ital j}{sub {ital s}} peak increase rapidly with decreasing {delta}. Approaching the stoichiometric state {delta}=0, the value of the current starts to decrease with lower oxygen deficiency, in contrast to the still increasing irreversibility field {ital B}{sub irr}. This points to the importance of oxygen disorder for the pinning and stresses the melting nature of the irreversibility line. The peak position {ital B}{sub max} is found to correlate with {ital B}{sub irr}. In the intermediate-temperature region, some of the samples showed a new second peak with weak temperature and {delta} dependence. The probable origin of this feature is matching with twin structure. This peak disappears formore » {delta}{gt}0.1, when the fishtail position shifts below the matching field. The low-temperature region is characterized by a monotonic decrease of {ital j}{sub {ital s}}({ital B}). This region becomes narrower with larger {delta} and disappears for {delta}{gt}0.3. Thus in highly deoxygenated samples, the fishtail feature is observed for practically all temperatures. The possible connection of the low-temperature region with the pinning of the small vortex bundles or with the slipping of vortices along the twin planes is considered.« less

Authors:
 [1];  [1]; ; ;  [2];  [3];  [1];  [3]; ;  [1]
  1. Kernforschungszentrum Karlsruhe, Institut fuer Technische Physik, Postfach 3640, D-76021 Karlsruhe (Germany)
  2. Centre for High Temperature Superconductivity, Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)
  3. Physics Department, Moscow State University, Moscow 117234 (Russian Federation)
Publication Date:
OSTI Identifier:
64020
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter
Additional Journal Information:
Journal Volume: 51; Journal Issue: 18; Other Information: PBD: 1 May 1995
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; HIGH-TC SUPERCONDUCTORS; MAGNETIZATION; COPPER OXIDES; BARIUM OXIDES; THULIUM OXIDES; YTTRIUM OXIDES; MAGNETIC FLUX; OXYGEN; STOICHIOMETRY; MONOCRYSTALS; MELTING POINTS

Citation Formats

Zhukov, A A, Physics Department, Moscow State University, Moscow 117234, Kuepfer, H, Perkins, G, Cohen, L F, Caplin, A D, Klestov, S A, Claus, H, Voronkova, V I, Wolf, T, and Wuehl, H. Influence of oxygen stoichiometry on the irreversible magnetization and flux creep in {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals. United States: N. p., 1995. Web. doi:10.1103/PhysRevB.51.12704.
Zhukov, A A, Physics Department, Moscow State University, Moscow 117234, Kuepfer, H, Perkins, G, Cohen, L F, Caplin, A D, Klestov, S A, Claus, H, Voronkova, V I, Wolf, T, & Wuehl, H. Influence of oxygen stoichiometry on the irreversible magnetization and flux creep in {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals. United States. https://doi.org/10.1103/PhysRevB.51.12704
Zhukov, A A, Physics Department, Moscow State University, Moscow 117234, Kuepfer, H, Perkins, G, Cohen, L F, Caplin, A D, Klestov, S A, Claus, H, Voronkova, V I, Wolf, T, and Wuehl, H. 1995. "Influence of oxygen stoichiometry on the irreversible magnetization and flux creep in {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals". United States. https://doi.org/10.1103/PhysRevB.51.12704.
@article{osti_64020,
title = {Influence of oxygen stoichiometry on the irreversible magnetization and flux creep in {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals},
author = {Zhukov, A A and Physics Department, Moscow State University, Moscow 117234 and Kuepfer, H and Perkins, G and Cohen, L F and Caplin, A D and Klestov, S A and Claus, H and Voronkova, V I and Wolf, T and Wuehl, H},
abstractNote = {The influence of the oxygen stoichiometry on magnetization and relaxation of {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R}=Y,Tm) single crystals was studied for 0{le}{delta}{le}0.55. The field dependences of the shielding currents {ital j}{sub {ital s}}({ital H}) and flux creep rates {ital S}({ital H}) were analyzed. Three different kinds of {ital j}{sub {ital s}}({ital H}) and {ital S}({ital H}) behavior can be seen in highly oxygenated samples ({delta}{lt}0.1). At high temperatures, {ital j}{sub {ital s}}({ital H}) shows a common fishtail peak, which is present for all oxygen contents. The field position and height of the {ital j}{sub {ital s}} peak increase rapidly with decreasing {delta}. Approaching the stoichiometric state {delta}=0, the value of the current starts to decrease with lower oxygen deficiency, in contrast to the still increasing irreversibility field {ital B}{sub irr}. This points to the importance of oxygen disorder for the pinning and stresses the melting nature of the irreversibility line. The peak position {ital B}{sub max} is found to correlate with {ital B}{sub irr}. In the intermediate-temperature region, some of the samples showed a new second peak with weak temperature and {delta} dependence. The probable origin of this feature is matching with twin structure. This peak disappears for {delta}{gt}0.1, when the fishtail position shifts below the matching field. The low-temperature region is characterized by a monotonic decrease of {ital j}{sub {ital s}}({ital B}). This region becomes narrower with larger {delta} and disappears for {delta}{gt}0.3. Thus in highly deoxygenated samples, the fishtail feature is observed for practically all temperatures. The possible connection of the low-temperature region with the pinning of the small vortex bundles or with the slipping of vortices along the twin planes is considered.},
doi = {10.1103/PhysRevB.51.12704},
url = {https://www.osti.gov/biblio/64020}, journal = {Physical Review, B: Condensed Matter},
number = 18,
volume = 51,
place = {United States},
year = {1995},
month = {5}
}