Synthesis of cobalt-based magnetic nanocrystals from cobalt (II) heterocyclic amine complexes Authors Authors and affiliations

چکیده مقاله

Cobalt nanocrystals with different morphologies and magnetic properties were prepared from three cobalt(II) heterocyclic amine precursors in alcoholic solution by a chemical reduction route. Complexes of cobalt(II) with heterocyclic amines such as pyridine, piperidine, and piperazine were reacted with hydrazine at 70 °C and pH 10–12. The obtained cobalt metallic nanocrystals (Co1–Co3) were characterized by using infrared (IR) spectroscopy, X-ray powder diffraction analysis, scanning electron microscopy, and vibrating-sample magnetometry. Powder X-ray diffraction patterns revealed the presence of two phases of hcp-Co and fcc-Co nanocrystals in the resulting cobalt metal. By changing the precursors, significant variation of magnetic properties and crystallite size was observed in Co1–Co3. This work provides new insight into the synthesis of metallic nanocrystals via chemical reduction of metal complexes and their magnetic properties.