Magnetic properties of the overdoped superconductorLa2−xSrxCuO4with and without Zn impurities

2005/03/31 by S. Wakimoto, Shuichi Wakimoto, R. J. Birgeneau +7 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Magnetic and transport properties of perovskites and related materials #Physics of Superconductivity and Magnetism #cond-mat.supr-con

paper · pdf · doi:10.1103/physrevb.72.064521

published as Phys. Rev. B 72, 064521 (2005) · 10 pages, 8 figures

openalex publication_date 2005/08/25 · arxiv created 2005/08/29 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28

Abstract

The magnetic properties of the Zn-substituted overdoped high-T_c superconductor La_2\ensuremath-xSr_xCu_1\ensuremath-yZn_yO₄ have been studied by magnetization measurements and neutron scattering. Magnetization measurements reveal that for Zn-free samples with x\ensuremath\geqslant0.22 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\phantom\rule0.3em0ex\ensuremathμ_B per additional Sr²⁺ ion that exceeds x=0.22. Zn substitution in the overdoped La_2\ensuremath-xSr_xCuO₄ also induces a Curie term that corresponds to 1.2\phantom\rule0.3em0ex\ensuremathμ_B per Zn²⁺ ion, simultaneously suppressing T_c. The relationship between T_c and the magnitude of the Curie term for Zn-free La_2\ensuremath-xSr_xCuO₄ with x\ensuremath\geqslant0.22 and for Zn-substituted La_2\ensuremath-xSr_xCuO₄ 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_2\ensuremath-xSr_xCuO₄ anomalously enhances the inelastic magnetic scattering spectra around the (\ensuremathπ,\ensuremathπ) position, peaking at \ensuremathω\ensuremath∼7\phantom\rule0.3em0exmeV. 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.

Citations

• Dispersion of Magnetic Excitations in Optimally Doped SuperconductingYBa2Cu3O6.95
• Novel In-Gap Spin State in Zn-DopedLa1.85Sr0.15CuO4
• Evolution of the resonance and incommensurate spin fluctuations in superconductingYBa2Cu3O6+x
• Exposing the spin-glass ground state of the nonsuperconductingLa2−xSrxCu1−yZnyO4high-Tcoxide
• Cu Nuclear Quadrupole Resonance Study of La2-xSrxCu1-yZnyO4(x=0.10, 0.15 and 0.20): Zn-induced Wipeout Effect near the Magnetic and Electric Instability
• Quantum magnetic excitations from stripes in copper oxide superconductors
• Spin pseudogap inLa2−xSrxCuO4studied by neutron scattering

Cited by

• Direct search for a ferromagnetic phase in a heavily overdoped nonsuperconducting copper oxide