Magnetic approach in some mixed Cobalt (II) hydroxynitrates compounds

Abstract
Among layered compounds, the transition metal hydroxynitrates M(OH) (NO .nH₂O (with M= Co, Ni,Cu) are still currently investigated, since they are good precursors for the synthesis of simple or mixed metal oxides with interesting catalytic and electronic properties.From a structural point of view, the hydroxynitrates derive from the CdI₂ type stucture of M (OH)₂. They can be described as 2D triangular arrays of metal ions with large interplanar distances, and accordingly, they are good candidates for studying bidimensional magnetic systems. Knowing that from a magnetic point view, Co(OH)₂ and Co₂(OH)₃(NO₃) were shown to be a genuine examples of layered ferromagnetic systems, with the occurrence of 3d antiferromagnetic order at nearly the same temperature ; we report in this paper the preparation and magnetic properties of layered cobat mixed metal(II) hydroxynitrates CoM(OH)₃(NO₃) (M= Cu, Ba) hydrated or no which display, according to the metal ion, either ferro or antiferromagnetic interlayer interactions. We discuss the interest in these compounds named hybrid organic-inorganic compounds for the stabilizing ferromagnetic interactions.