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Anisotropic Magnetoresistance in Charge-Ordering $Na_{0.34}(H_3O)_{0.15}CoO_2$:Strong Spin-Charge Coupling and Spin Ordering

C. H. Wang·X. H. Chen·G. Wu·T. Wu·H. T. Zhang·J. L. Luo·G. T. Liu·N. L. Wang
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Abstract

Angular-dependent in-plane magnetoresistance (AMR) for single crystal $Na_{0.34}(H_3O)_{0.15}CoO_2$ with charge ordering is studied systematically. The anisotropic magnetoresistance shows a twofold symmetry at high temperature with rotating H in the Co-O plane, while a sixfold symmetry below a certain temperature ($T_ρ$). At $T_ρ$, the symmetry of AMR changes from twofold to fourfold with rotating magnetic field (H) in the plane consisting of the current and c-axis. The variation of AMR symmetry with temperature arises from the subtle changes of the spin structure. These results give a direct evidence for the itinerant electrons directly coupled to the localized spins.

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C. H. Wang, X. H. Chen, G. Wu, T. Wu, H. T. Zhang, J. L. Luo, G. T. Liu, N. L. Wang. 2006-07-22. Anisotropic Magnetoresistance in Charge-Ordering $Na_{0.34}(H_3O)_{0.15}CoO_2$:Strong Spin-Charge Coupling and Spin Ordering. https://doi.org/10.1103/physrevb.74.172507

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