Search for Magnetic Excitation Spectra of NaxCoO2.yD2O -Neutron Scattering-

Abstract

Neutron inelastic scattering studies on aligned crystals of NaxCoO2.yD2O have been carried out. Significant scattering has been observed for phonons originating from the vibrations of the short-range ordered D2O molecules. No firm evidence for the magnetic fluctuations has been found for the NaxCoO2.yD2O, while the very weak intensity modulation observed in the j scans along (1/2, 1/2, j) suggests the existence of the antiferromagnetic fluctuations in the non-deuterated parts of the sample, the volume fraction of which is estimated to be about 26 %. The present results indicate that magnetic fluctuations, especially ferromagnetic ones are rather weak, in the deuterated system, which is consistent with the results of the NMR Knight shift reported by the present authors' group. We discuss the short-range ordered state of D2O, too by analyzing the observed diffuse scattering.

6 pages, 8 figures

References in corpus (3)

• Fermi surface and quasiparticle dynamics of Na(x)CoO2 {x=0.7} investigated by Angle-Resolved Photoemission Spectroscopy
• ARPES on Na${}_{0.6}$CoO${}_2$: Fermi surface, extended flat dispersion, and unusual band splitting
• Three-Dimensional Spin Fluctuations in Na0.75CoO2

Cited by in corpus (5)

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• Magnetic properties of superconducting cobalt oxides NaxCoO2.yH2O
• CoO2-Layer-Thickness Dependence of Magnetic Properties and Possible Two Different Superconducting States in NaxCoO2.yH2O
• s-wave Superconductivity due to Suhl-Kondo Mechanism in Na${}_x$CoO${}_2\cdot y$H${}_2$O: Effect of Coulomb Interaction and Trigonal Distortion
• Co-NMR Knight Shift of NaxCoO2 \dot yH2O Studied in Both Superconducting Regions of the Tc-nuQ3 Phase Diagram Divided by the Nonsuperconducting Phase