Na ordering and Co magnetism in a metallic antiferromagnet Na_{0.825}CoO_{2}

Ben-Li Young; P.-Y. Chu; J. Y. Juang; G.J. Shu; F.C. Chou

Na ordering and Co magnetism in a metallic antiferromagnet Na$_{0.825}$CoO$_{2}$

POSTER

Abstract

Sodium cobaltate, Na$_{x}$CoO$_{2}$, originally known as a battery material, has shown other prominent features such as thermoelectricity, magnetism, and superconductivity. For certain Na contents, the Na vacancies are not randomly distributed so that a superlattice structure is formed. We investigated the Na ordering and the Co magnetism in the $x=$0.825 phase of a metallic antiferromagnet, by nuclear magnetic-resonance (NMR) techniques. We successfully derived the three-dimensional superstructure of the Na ordering, and found additional magnetic susceptibility component emerging at 60 K. In addition, a magnetic field-induced glassy behavior near a metamagnetic transition was discovered.

^*This work was supported by NSC Grants No. 98-2112-M-009-016-MY3 and No. 101-2112-M-009-015-MY2 and by the MOE ATU Program operated at NCTU.

Authors

Ben-Li Young
- Department of Electrophysics, National Chiao Tung University, Taiwan
P.-Y. Chu
- Department of Electrophysics, National Chiao Tung University, Taiwan
J. Y. Juang
- Department of Electrophysics, National Chiao Tung University, Taiwan
G.J. Shu
- Center for Condensed Matter Sciences, National Taiwan University, Taiwan
F.C. Chou
- Center for Condensed Matter Sciences, National Taiwan University, Taiwan