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Cobalt-based perovskites incorporating rare-earth elements at the A-site, partially substituted with alkali and alkaline-earth cations, have attracted considerable attention for their potential applications in solid oxide fuel cells and catalytic processes [1]. Among them, praseodymium-cobalt perovskites stand out as a particularly interesting class of materials, combining structural complexity with promising functional properties. This study focuses on their synthesis and characterization, and the influence of the rare-earth substitution on their structural stability and properties.
For the synthesis of Pr1-xAxCoO3, where A = K and Ca, the EDTA-citric acid complexing method was used. In this approach, EDTA acts as a chelating agent [2], ensuring controlled distribution of metal ions and promoting the formation of homogeneous particles with nanoscale dimensions, while citric acid is used as fuel.
The obtained perovskites were investigated by X-ray powder diffraction (XRD) and Infrared (IR) spectroscopy. The diffraction patterns confirm their purity and the degree of crystallinity, while the comparison with the unsubstituted Pr-perovskites with the corresponding metals indicates that the obtained compounds adopt an orthorhombic structure.
Further investigation and characterization was carried out using vibrational spectroscopy techniques such as IR spectroscopy in the mid-infrared (MIR) and far-infrared (FIR) region in order to probe the lattice dynamics and structural features of the obtained perovskites.