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Title: Hyperfine fields at the Ba site in the antiferromagnet YBa{sub 2}Cu{sub 3}O{sub 6.05}

Abstract

We report a Ba nuclear quadrupole resonance (NQR) study of the antiferromagnetic state of YBa{sub 2}Cu{sub 3}O{sub 6.05} (N{acute e}el temperature {ital T}{sub {ital N}} = 415 K) performed between 16 and 402 K. The Zeeman perturbed {sup 137}Ba NQR spectrum yields information on two hyperfine fields present at the Ba site: the electric field gradient (EFG) and the internal magnetic field arising from the Cu(2) sublattice magnetization. The absolute value of the EFG is in remarkable agreement with cluster and band structure calculations thus demonstrating again that both methods provide a satisfying electronic bond picture for the Y-Ba-Cu-O compounds [except for the planar Cu(2) site]. The temperature dependence of the EFG arises from thermal expansion only. The internal field, {ital B}({ital T}), has been deduced from the modulation of the Ba spin-echo intensity. A calculation of the dipolar field at the Ba site produced by Cu(2) {ital d} electrons yields a value that is about three times larger than the experimental result. The discrepancy could be explained by assuming that part of the magnetic moment is located at oxygen ions. The temperature variation of {ital B}({ital T}) follows, up to 402 K, a power law [{ital B}(0){minus}{ital B}({ital T})]/{italmore » B}(0)={ital AT}{sup {alpha}} with {alpha} = 1.82(22) which agrees quite well with the result of a Cu(2) in-plane determination of the sublattice magnetization. Furthermore, this result is in accord with a spin-wave model for a quasi-two-dimensional (2D) antiferromagnet. The {open_quote}{open_quote}critical exponent{close_quote}{close_quote} {beta} is estimated to be {le} 0.18 which is in accord with values proposed by models for 2D ordered magnetic systems. Thus YBa{sub 2}Cu{sub 3}O{sub 6.05} behaves, in terms of its spin dynamics, as a quasi-2D antiferromagnet and this character can be studied either at out-of-plane Ba or at in-plane Cu(2) sites. {copyright} {ital 1996 The American Physical Society.}« less

Authors:
; ; ;  [1]
  1. Physik-Institut, Universitaet Zuerich, CH-8057 Zuerich (Switzerland)
Publication Date:
OSTI Identifier:
284384
Resource Type:
Journal Article
Journal Name:
Physical Review, B: Condensed Matter
Additional Journal Information:
Journal Volume: 53; Journal Issue: 21; Other Information: PBD: Jun 1996
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; HIGH-TC SUPERCONDUCTORS; HYPERFINE STRUCTURE; ANTIFERROMAGNETIC MATERIALS; COPPER OXIDES; BARIUM OXIDES; YTTRIUM OXIDES; NUCLEAR QUADRUPOLE RESONANCE; NEEL TEMPERATURE; ELECTRIC FIELDS; MAGNETIC FIELDS; MAGNETIZATION; THERMAL EXPANSION; SPIN ECHO; TEMPERATURE DEPENDENCE; SPIN WAVES; ELECTRIC FIELD GRADIENTS; CRITICAL EXPONENTS

Citation Formats

Lombardi, A, Mali, M, Roos, J, and Brinkmann, D. Hyperfine fields at the Ba site in the antiferromagnet YBa{sub 2}Cu{sub 3}O{sub 6.05}. United States: N. p., 1996. Web. doi:10.1103/PhysRevB.53.14268.
Lombardi, A, Mali, M, Roos, J, & Brinkmann, D. Hyperfine fields at the Ba site in the antiferromagnet YBa{sub 2}Cu{sub 3}O{sub 6.05}. United States. https://doi.org/10.1103/PhysRevB.53.14268
Lombardi, A, Mali, M, Roos, J, and Brinkmann, D. 1996. "Hyperfine fields at the Ba site in the antiferromagnet YBa{sub 2}Cu{sub 3}O{sub 6.05}". United States. https://doi.org/10.1103/PhysRevB.53.14268.
@article{osti_284384,
title = {Hyperfine fields at the Ba site in the antiferromagnet YBa{sub 2}Cu{sub 3}O{sub 6.05}},
author = {Lombardi, A and Mali, M and Roos, J and Brinkmann, D},
abstractNote = {We report a Ba nuclear quadrupole resonance (NQR) study of the antiferromagnetic state of YBa{sub 2}Cu{sub 3}O{sub 6.05} (N{acute e}el temperature {ital T}{sub {ital N}} = 415 K) performed between 16 and 402 K. The Zeeman perturbed {sup 137}Ba NQR spectrum yields information on two hyperfine fields present at the Ba site: the electric field gradient (EFG) and the internal magnetic field arising from the Cu(2) sublattice magnetization. The absolute value of the EFG is in remarkable agreement with cluster and band structure calculations thus demonstrating again that both methods provide a satisfying electronic bond picture for the Y-Ba-Cu-O compounds [except for the planar Cu(2) site]. The temperature dependence of the EFG arises from thermal expansion only. The internal field, {ital B}({ital T}), has been deduced from the modulation of the Ba spin-echo intensity. A calculation of the dipolar field at the Ba site produced by Cu(2) {ital d} electrons yields a value that is about three times larger than the experimental result. The discrepancy could be explained by assuming that part of the magnetic moment is located at oxygen ions. The temperature variation of {ital B}({ital T}) follows, up to 402 K, a power law [{ital B}(0){minus}{ital B}({ital T})]/{ital B}(0)={ital AT}{sup {alpha}} with {alpha} = 1.82(22) which agrees quite well with the result of a Cu(2) in-plane determination of the sublattice magnetization. Furthermore, this result is in accord with a spin-wave model for a quasi-two-dimensional (2D) antiferromagnet. The {open_quote}{open_quote}critical exponent{close_quote}{close_quote} {beta} is estimated to be {le} 0.18 which is in accord with values proposed by models for 2D ordered magnetic systems. Thus YBa{sub 2}Cu{sub 3}O{sub 6.05} behaves, in terms of its spin dynamics, as a quasi-2D antiferromagnet and this character can be studied either at out-of-plane Ba or at in-plane Cu(2) sites. {copyright} {ital 1996 The American Physical Society.}},
doi = {10.1103/PhysRevB.53.14268},
url = {https://www.osti.gov/biblio/284384}, journal = {Physical Review, B: Condensed Matter},
number = 21,
volume = 53,
place = {United States},
year = {1996},
month = {6}
}