Size-controlled synthesis, growth mechanism and magnetic properties of cobalt microspheres

Monodispersed cobalt microspheres with remarkably uniform morphology and tunable size have been successfully synthesized via a facile and effective solvothermal route. It is found that sodium hydroxide has a great influence on the size and shape of the resulting cobalt powders. Through adjusting the molar ratio of NaOH to Co2+, the size of cobalt microspheres can be precisely manipulated. In addition, the magnetic properties of the as-synthesized samples demonstrate that cobalt microspheres exhibit ferromagnetic property related to their sizes. More importantly, this study not only provides a facile and effective strategy to prepare the cobalt microspheres with tunable sizes, but also gives a reference for the synthesis of other magnetic functional materials.