NMR Study of Carrier Doping Effects on Spin Gaps in the Spin Ladder Sr{sub 14-{ital x}}A{sub {ital x}}Cu{sub 24}O{sub 41} ({ital A}=Ca, Y, and La)

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.78.1992· OSTI ID:475704

Kumagai, K; Tsuji, S ^[1]; Kato, M; Koike, Y ^[2]

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1. Department of Physics, Graduate School of Science, Hokkaido University, Sapporo 060 (Japan)
2. Department of Applied Physics, Faculty of Engineering, Tohoku University, Sendai 980-77 (Japan)

Carrier doping effects on spin dynamics in Sr{sub 14-x}A{sub x}Cu{sub 24}O{sub 41} (A=Ca, Y, and La) are investigated by Cu NMR and NQR. The energy gaps in the spin excitation spectra (spin gap) are confirmed to be {Delta}=140K for the CuO{sub 2} chain and {Delta}=470K for the Cu{sub 2}O{sub 3} ladder in Sr{sub 14}Cu{sub 24}O{sub 41}. The spin gap for the ladder increases with the Y and La substitutions for Sr (up to x=3), while it decreases with increasing {ital x} in Sr{sub 14-x}Ca{sub x}Cu{sub 24}O{sub 41} and seems to collapse around x=13 of the Ca substitution. Hole-doping effects on the spin gaps for the ladder configuration are interpreted in terms of magnon and hole-depairing excitations for the spin S=(1)/(2) ladder. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 475704
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 10 Vol. 78; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
66 PHYSICS
ANTIFERROMAGNETIC MATERIALS
CALCIUM OXIDES
COPPER OXIDES
DOPED MATERIALS
ENERGY GAP
HIGH-TC SUPERCONDUCTORS
LANTHANUM OXIDES
MAGNONS
NMR SPECTRA
SPIN ORIENTATION
STRONTIUM OXIDES
YTTRIUM OXIDES