The impact of magnetic dilution on magnetic order in MnPS3

MnPS3 is a layered honeycomb lattice antiferromagnet with the spins aligned perpendicular to the layers at low temperature. Structurally it is monocli nic, with an unusual combination of magnetic and crystallographic symmetrie s, and so offers a rare insight into the behaviour of low-dimensional magne tism. Here the effect of magnetic dilution by Zn substitution on the magnet ic structure is explored using neutron diffraction and magnetometry. The co mposition dependencies of TN and the spin hop held are found. The critical concentration for long-range order is estimated to be 45% Mn. The first nei ghbour exchange is found to be independent of composition. It appears that dilution induces a moment component in the plane, and gives rise to a compl ex phase diagram in which a reordering temperature is apparent.