Ising-like Magnetism in Quasi-Two-Dimensional Co(NO)·2HO.

The appearance of electrically neutral water molecules in the structure of cobalt dinitrate dihydrate, Co(NO)⋅2HO, drastically changes its magnetic properties as compared to its waterless counterpart, Co(NO). The title compound shows Ising-like behavior reflected in its thermodynamic properties. It experiences long-range antiferromagnetic order at = 20.5 K and metamagnetic transition at = 0.76 T. First-principles calculations produce the values of leading exchange interactions ~ 10 K and ~ 0.5 K and single-ion anisotropy ~ 1 K which allows us to consider Co(NO)⋅2HO as a quasi-two-dimensional magnetic system.