Microwave-assisted solution combustion synthesis and characterization of thermoelectric Ca3Co2O6 powders

The microwave-assisted solution combustion synthesis was applied to the initial synthesizing of Ca3Co2O6 powder using glycine as a fuel and nitrate as an oxidant. The as-synthesized powders were calcined at 700-1,000 degrees C for 4h. Product characterization was performed using Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Scanning electron microscope (SEM). The fuel-to-oxidizer molar ratio was found to affect the combustion reaction and character of the powder obtained. The phase composition of powder after calcination at various temperatures has shown that the formation of Ca3Co2O6 occurs directly. The calcined powder possesses a rhombohedral crystal structure with an X-ray diffraction pattern that could be matched with the Ca(3)Co(2)O(6)JCPDS: 89-0629. This method is a simple way of synthesizing fine Ca3Co2O6 powder with a low calcination temperature.