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NiCo2TeO6 crystallises in the R3 space group where the displacements of the O1/O2 oxygen atoms in the triangular plaquettes lead to left-handed and right-handed structural chiralities [1]. This compound is particularly interesting because an anomaly was observed in the dielectric susceptibility at TN suggesting the presence of magnetoelectric behaviour [2]. A long-range magnetic order (magnetic space group R3.1’(00ɣ)ts) develops below 52 K consisting of ferromagnetically coupled a-b layers of Ni2+ that rotate along c with an incommensurate propagation vector k = (0, 0, 0.211) [2]. It is not yet clear if the magnetic helix echoes the feature of two helices of opposite handedness where the globally preferred chirality emerges as a difference between the displacements or if it presents a single chirality. Therefore, we probed the structural and magnetic chiralities using polarized neutrons on the D3 diffractometer at the ILL, following the successful methodology from our previous work on a langasite compound [3]. We studied two NiCo2TeO6 single crystals, one of each structural chirality. Spherical neutron polarimetry and Schwinger scattering were exploited to deduce the magnetic and structural chiralities, respectively, while our complementary X-rays results yield information concerning the coupling of those two quantities. Our findings constitute an important step towards the understanding of the magnetoelectric properties of this compound.
[1] X. Wang et al., APL Meterials, 3(7) (2015) 076105.
[2] S. Skiadopoulou et al., Phys. Rev B, 101(1) (2020) 014429.
[3] N. Qureshi et al., Phys. Rev B, 102(4) (2020) 054417.
