Synthesis, structure and magnetic properties of a tin cobalt phosphate framework, SnCo2(H2O)2(PO4)2 · H2O

The hydrothermal inorganic reaction of cobalt chloride, tin oxalate and phosphoric acid yields a three-dimensional metal phosphate structure containing cobaltate layers. Hydrated tin phosphate chains connect the layers, defining unidimensional channels that contain occluded water molecules. Thermal and magnetic behaviour are also discussed. A cusp around 3.5 K and a negative Curie temperature of −35.9 K indicate antiferromagnetic exchange interactions between the Co(II) centers in the solid. The magnetic behavior follows the Curie–Weiss law in the 25–300 K range, with an effective magnetic moment of 3.18 μB.