Characterization of Y2Cu2O5 powder prepared by citric acid complex method

Abstract

In this study, Y2Cu2O5 (YCO225) powders were prepared using a citric acid complex method, and the thermally decomposed products were characterized by powder X-ray diffraction, scanning electron microscopy (SEM), and UV–vis spectroscopy measurements. A single phase of YCO225 was obtained after calcination at 750 °C in air. The temperature is approximately 350 °C lower than the temperature at which a single phase of YCO225 appears by the solid-state reaction. From SEM observations, inter-particle sintering of YCO225 progressed and the particle size increases parabolically as the heating temperature increased. In the UV–vis measurement, YCO225 showed a charge-transfer type absorption from O2– to Cu2+ ions in the wavelength region shorter than 500 nm. In addition, absorption due to d-d transitions of Cu2+ ions appeared around 600, 710, and 860 nm, which were attributed to 2B1g→2A1g, 2B1g→2Eg, and 2B1g→2B2g, respectively. Furthermore, the greenness (-a* value) of YCO225 fired at 950 °C was found to be 27.9, which was greater than the greenness of commercial chrome green (Cr2O3, -a* = 15.0).