Are the double periodicity of CM phase and coexistence of ICM phase a generalized property of Ni-based honeycomb spin systems A2Ni2TeO6 ?

Honeycomb lattice AFM based on layered transition metal oxides are of special interest. For layer honeycomb AFM Na2Ni2TeO6, two unique features, (i) the double periodicity (UUDD) of the 3D commensurate AFM order, and (ii) the coexistence of a 2D incommensurate AFM order, are reported to be related to the symmetry of the intermediate Na layers. Here, we propose neutron diffraction study, using the GEM diffractometer, on the related compound Li2Ni2TeO6 to determine the temperature dependent spin-spin correlations, effect of ionic size, and to validate the role of the intermediate alkali metal layer on the magnetic symmetry. The outcome of the proposed study will shed light on the theoretically predicted ground states for honeycomb spin systems in general, and clarify whether the dictation of the magnetic symmetry by the intermediate alkali layer is universal or not.