Magnetic properties of the overdoped superconductor La{sub 2-x}Sr{sub x}CuO{sub 4} with and without Zn impurities

Journal Article · Mon Aug 01 00:00:00 EDT 2005 · Physical Review. B, Condensed Matter and Materials Physics

DOI:https://doi.org/10.1103/PhysRevB.72.064521· OSTI ID:20719321

Wakimoto, S ^[1]; Birgeneau, R J ^[1]; Kagedan, A; Kim, Hyunkyung; Zhang, H ^[1]; Swainson, I ^[2]; Yamada, K ^[3]

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1. Department of Physics, University of Toronto, Toronto, Ontario, M5S 1A7 (Canada)
2. Neutron Program for Materials Research, National Research Council of Canada, Chalk River, Ontario, K0J 1J0 (Canada)
3. Institute of Material Research, Tohoku University, Katahira, Sendai 980-8577 (Japan)

The magnetic properties of the Zn-substituted overdoped high-T{sub c} superconductor La{sub 2-x}Sr{sub x}Cu{sub 1-y}Zn{sub y}O{sub 4} have been studied by magnetization measurements and neutron scattering. Magnetization measurements reveal that for Zn-free samples with x{>=}0.22 a Curie term is induced in the temperature dependence of the magnetic susceptibility implying the existence of local paramagnetic moments. The induced Curie constant corresponds to a moment of 0.5 {mu}{sub B} per additional Sr{sup 2+} ion that exceeds x=0.22. Zn substitution in the overdoped La{sub 2-x}Sr{sub x}CuO{sub 4} also induces a Curie term that corresponds to 1.2 {mu}{sub B} per Zn{sup 2+} ion, simultaneously suppressing T{sub c}. The relationship between T{sub c} and the magnitude of the Curie term for Zn-free La{sub 2-x}Sr{sub x}CuO{sub 4} with x{>=}0.22 and for Zn-substituted La{sub 2-x}Sr{sub x}CuO{sub 4} with x=0.22 are closely similar. This signifies a general competitive relationship between the superconductivity and the induced paramagnetic moment. Neutron scattering measurements show that Zn substitution in overdoped La{sub 2-x}Sr{sub x}CuO{sub 4} anomalously enhances the inelastic magnetic scattering spectra around the ({pi},{pi}) position, peaking at {omega}{approx}7 meV. These facts are discussed on the basis of a 'swiss-cheese' model of Zn-substituted systems as well as a microscopic phase separation scenario in the overdoped region indicated by muon-spin-relaxation measurements.

• OSTI ID: 20719321
• Journal Information: Physical Review. B, Condensed Matter and Materials Physics, Vol. 72, Issue 6; Other Information: DOI: 10.1103/PhysRevB.72.064521; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CUPRATES
CURIE POINT
HIGH-TC SUPERCONDUCTORS
LANTHANUM COMPOUNDS
MAGNETIC SUSCEPTIBILITY
MAGNETIZATION
MUON PROBES
MUON SPIN RELAXATION
NEUTRON DIFFRACTION
PARAMAGNETISM
STRONTIUM COMPOUNDS
STRONTIUM IONS
SUPERCONDUCTIVITY
TEMPERATURE DEPENDENCE
ZINC IONS