The synthesis and microstructure of CuFeO₂ powders via microwave hydrothermal reaction

Abstract

The CuFeO₂ powders have been synthesized by the microwave hydrothermal reaction at different reaction temperatures. The pure rhombohedral phase for CuFeO₂ has been formed and confirmed by the X-ray diffraction (XRD). The microstructure and morphology for all CuFeO₂ samples have been scanned by the Transmission Electronic Microscope (TEM). Various scales of grains for powders have been found spanning from several nanometers to hundreds of nanometers, and even few scales are over 1 µm for some grains. The average grain sizes for all powders have been calculated basing on the XRD patterns to show the changing of grain sizes with the temperature. The distributions of the grain size have also been studied by counting grain numbers from the TEM images. Based on the above results, the mechanism of grain growth has been analyzed and found to be the classical Ostwald ripening.