paper

Susceptibility anisotropy and absence of ferroelectric order in the Kitaev spin liquid candidate Na $_{2}$ Co $_{2}$ TeO $_{6}$

arXiv:2502.01580 · doi:10.1016/j.cjph.2025.08.010

Abstract

We report the magnetic, magnetodielectric, and electric polarization properties of single crystals of the Co-based Kitaev Spin Liquid (KSL) candidate Na $_{2}$ Co $_{2}$ TeO $_{6}$ (NCTO). The sample shows magnetic transitions at 26 K, 16 K, and 5 K, consistent with the literature. The magnetic measurements along and perpendicular to the Co-honeycomb planes show a strong anisotropy in susceptibility and in Curie-Weiss (C-W) temperatures. The experimental anisotropic C-W temperatures of NCTO qualitatively match with the theoretical C-W temperatures, calculated using the HKTF model [C. Kim \textit{et al.}, J. Phys.: Condens. Matter \textbf{34}, 045802 (2021)]. We find from our temperature- and field-dependent dielectric and pyroelectric ( $I_{p}$ ) current studies ( $H ∥ ab$ and $E ⊥ ab$ ) that our single crystal NCTO samples do not have a finite electric polarization below 100 K. These $I_{p}$ studies confirm the absence of a magnetoelectric coupling and electric polarization properties in the title compound and suggest that the zig-zag AFM structure is more favorable than the triple- $Q$ structure with AFM Kitaev interactions.

7 pages, 6 figures, 2 tables

Susceptibility anisotropy and absence of ferroelectric order in the Kitaev spin liquid candidate Na2​Co2​TeO6​

Abstract

Susceptibility anisotropy and absence of ferroelectric order in the Kitaev spin liquid candidate Na $_{2}$ Co $_{2}$ TeO $_{6}$