Spin correlation and spin gap in quasi-one-dimensional spin-1/2 cuprate oxides: A {sup 63}Cu NMR study

Journal Article · Thu Feb 01 04:00:00 EST 1996 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.53.2827· OSTI ID:282798

Ishida, K; Kitaoka, Y; Tokunaga, Y; Matsumoto, S; Asayama, K ^[1]; Azuma, M; Hiroi, Z; Takano, M ^[2]

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1. Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka-fu 560 (Japan)
2. Institute for Chemical Research, Kyoto University, Uji, Kyoto-fu 611 (Japan)

The Cu-NMR nuclear relaxation rate, {sup 63}(1/{ital T}{sub 1}) and Gaussian spin-echo decay rate, {sup 63}(1/{ital T}{sub 2{ital G}}) have been measured in order to investigate the low-energy spin dynamics in the quasi 1-D spin-1/2 antiferromagnetic (AF) cuprates such as Ca{sub 2}CuO{sub 3} with single chain, SrCuO{sub 2} at ambient pressure (AP) with zigzag chain coupled by weak ferromagnetic exchange interaction, SrCu{sub 2}O{sub 3} and Sr{sub 2}Cu{sub 3}O{sub 5} comprising of two- and three-leg ladder, respectively with isotropic AF exchange interaction along and between chains. In Ca{sub 2}CuO{sub 3}, 1/{ital T}{sub 1} stays constantly close to the 3D magnetic ordering temperature, {ital T}{sub {ital N}} =10 K, dominated by dissipation of overdamped spinons gas as shown by Sachdev. By contrast, in AP-SrCuO{sub 2}, 1/{ital T}{sub 1} below 100 K decreases markedly down to the 3D magnetic ordering temperature, {ital T}{sub {ital N}} =3 K, providing a signature that the frustrated ferromagnetic interaction between CuO zigzag chains makes the spin gap open. In the spin-1/2 ladder compounds of SrCu{sub 2}O{sub 3} and Sr{sub 2}Cu{sub 3}O{sub 5} consisting of two- and three-leg, respectively, the former was demonstrated in the literatures to have the spin gap amounting to a half of AF exchange constant, {ital J}/2 where {ital J}=1300 K. For the latter, the magnetic coherence length, {xi}({ital T}) grows up according to {xi}({ital T}){approximately}1/({ital T}{minus}{theta}) and as a result, the magnetic ordering emerges around 50-60 K accompanying the divergence of 1/{ital T}{sub 1}. In the compounds composed of single and triple chains, it is shown that there is no analog of renormalized classical region identified in the 2D spin-1/2 cuprate such as La{sub 2}CuO{sub 4}, but the spin dynamics is in the quantum critical regime over wide {ital T} range due to the finite size of chains, even though the 3D magnetic ordering takes place at very low temperature.

• OSTI ID: 282798
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 5 Vol. 53; ISSN 0163-1829; ISSN PRBMDO
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ANTIFERROMAGNETIC MATERIALS
CALCIUM OXIDES
CHAINS
COPPER 63
CUPRATES
ENERGY GAP
EXCHANGE INTERACTIONS
LANTHANUM OXIDES
LINEAR CHAINS
NMR SPECTRA
ONE-DIMENSIONAL SYSTEMS
RELAXATION TIME
SPIN
SPIN CORRELATIONS
SPIN ECHO
STRONTIUM OXIDES