  Recent theoretical studies have suggested that the low-energy Hamiltonian of
honeycomb cobaltate systems could be dominated by anisotropic Kitaev
interactions. Motivated by the theory, a honeycomb layered material
Na$_{2}$Co$_{2}$TeO$_{6}$ with a hexagonal unit cell has been studied and found
to exhibit antiferromagnetic (AFM) ordering at 27 K with two spin reorientation
transitions at 15 and 5 K. Here we report a monoclinic polymorph of
Na$_{2}$Co$_{2}$TeO$_{6}$, also with honeycomb layered structure but with a
single AFM transition at 9.6 K and without spin reorientation transitions at
lower temperatures. Using neutron diffraction, we identify an in-plane zigzag
AFM order in the ground-state with the spins canted out of the honeycomb planes
and ferromagnetically coupled between them. The zigzag order is suppressed by a
magnetic field of 6 T.
