Structure and magnetism of the mono-layer hydrate Na0.3NiO2 ⋅ 0.7H2O

The mono-layer hydrate (Ni-MLH) Na0.3NiO2⋅0.7H2O was synthesized with an average Ni valence close to one in the bi-layer hydrate (Ni-BLH) Na0.3NiO2⋅1.3H2O. A weak unsaturated ferromagnetism and divergence of the magnetic susceptibilities of field and zero-field cooled samples of both Ni-MLH and Ni-BLH are observed. However, as a result of the increased three-dimensional electronic and magnetic character present in Ni-MLH, a frequency dependence of the AC magnetic susceptibility indicative of spin-glass-like behavior, as seen in Ni-BLH, was no longer observed.