Effects of pulsed electromagnetic field on morphology and size of cobalt oxalate particles

Abstract

It is of much significance to control the morphology and size of cobalt oxalate precursor for the preparation of cobalt powders. The cobalt oxalate powders were prepared by conventional precipitation at different initial cobalt chloride concentrations in the presence of pulsed electromagnetic field. Scanning electron microscopy images and size analysis indicate that spherical and fine cobalt oxalate particles with uniform size are obtained. Conductivity analysis demonstrates that pulsed electromagnetic field plays an important role in the preparation of monodisperse cobalt oxalate particles owing to the inhibition of the secondary nucleation. X-ray powder diffraction results show the formation of β-CoC₂O₄·2H₂O with a micro-size change of cobalt oxalate grain when the extra pulsed electromagnetic field is present. Fourier transform infrared spectroscopy results indicate that the transition of bond way in CoC₂O₄·2H₂O favours to develop stable crystal nucleus. Besides, a possible mechanism for the interaction between pulsed electromagnetic field and cobalt oxalate reaction system was preliminarily discussed.

Keywords:

• Cobalt oxalate powder
• Morphology
• Size
• Pulsed electromagnetic field
• Chemical precipitation

Acknowledgements

This work was supported by Natural Science Foundation of Liaoning Province of China (No. 201202096) and the Scientific Research Fund for Teachers of Liaoning University of Technology (No. X201114).