Electronic structure, magnetic and dielectric properties of the edge-sharing copper-oxide chain compound NaCu${}_2$O${}_2$

Abstract

We report an experimental study of \nco, a Mott insulator containing chains of edge-sharing CuO${}_4$ plaquettes, by polarized x-ray absorption spectroscopy (XAS), resonant magnetic x-ray scattering (RMXS), magnetic susceptibility, and pyroelectric current measurements. The XAS data show that the valence holes reside exclusively on the Cu${}^{2+}$ sites within the copper-oxide spin chains and populate a $d$-orbital polarized within the CuO${}_4$ plaquettes. The RMXS measurements confirm the presence of incommensurate magnetic order below a Néel temperature of $T_N=11.5$ K, which was previously inferred from neutron powder diffraction and nuclear magnetic resonance data. In conjunction with the magnetic susceptibility and XAS data, they also demonstrate a new "orbital" selection rule for RMXS that is of general relevance for magnetic structure determinations by this technique. Dielectric property measurements reveal the absence of significant ferroelectric polarization below $T_N$, which is in striking contrast to corresponding observations on the isostructural compound \lco. The results are discussed in the context of current theories of multiferroicity.

7 pages, 7 figures

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• Spin current and magneto-electric effect in non-collinear magnets
• Role of the Dzyaloshinskii-Moriya interaction in multiferroic perovskites
• Correlation between spin helicity and electric polarization vector in quantum-spin chain magnet LiCu${}_2$O${}_2$
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• Multiferroicity in the spin-1/2 quantum matter of LiCu2O2
• Wigner crystallization in Na(3)Cu(2)O(4) and Na(8)Cu(5)O(10) chain compounds
• Nonrelativistic Multiferroicity in the Nonstoichiometric Spin s=1/2 Spiral Chain Cuprate LiCu2O2
• Multiferroicity due to nonstoichiometry in the chain cuprate LiVCuO_4
• Microscopic mechanisms of spin-dependent electric polarization in 3d oxides
• Exciton doublet in the Mott-Hubbard LiCuVO${}_4$ insulator identified by spectral ellipsometry
• Incommensurate spin density modulation in a copper-oxide chain compound with commensurate charge order

Cited by in corpus (10)

• Resonant Elastic Soft X-Ray Scattering
• Symmetry analysis of magneto-optical effects: The case of x-ray diffraction and x-ray absorption at the transition metal L23 edge
• Thermodynamic Properties of the Anisotropic Frustrated Spin-chain Compound Linarite PbCuSO${}_4$(OH)${}_2$
• Magnetic structure of the edge-sharing copper oxide chain compound NaCu2O2
• Ground State of the Quasi-1D \bvs\ resolved by Resonant Magnetic X-ray Scattering
• Exotic phases of frustrated antiferromagnet LiCu2O2
• Anisotropic Exchange in $\mathbf{LiC}{\mathbf{u}}_2{\mathbf{O}}_2$
• Bond distortion effects and electric orders in spiral multiferroic magnets
• Anisotropic optical response of the mixed-valent Mott-Hubbard insulator NaCu2O2
• Magnetic Scattering Chapter