Synthesis of Co3[Fe(CN)6]2 molecular-based nanomagnets in MSU mesoporous silica by integrative chemistry

Abstract

Nanometric particles of Co₃[Fe(CN)₆]₂ magnetic cyano-bridged polymers have been synthesised by the combination of the direct synthesis of mesoporous MSU-type silica and the parallel reaction of cobalt nitrate with potassium ferricyanide. This synthesis, relevant to integrative chemistry methods, allowed us to confine the particle growth during the building of the mesostructured framework of silica. The obtained composite materials were studied by XRD, SAXS, TEM and FT-IR. Magnetic measurements of the nanoparticles extracted after silica dissolution by HF treatment, confirmed the expected magnetic behaviour of these Prussian Blue analogues. Compared with bulk materials, a spin-glass like regime is observed due to the presence of strong interparticle magnetostatic interactions between the nanoparticles which appeared as a result of the high density of nanoparticles in the nanocomposite materials synthesised by this new method.