Sol-gel synthesis of cubic Nb/Ta-doped SrCoO_{3−<i>δ</i>} with mixed nano-micro morphology

Abstract

SrCo 0.90 M 0.10 O 3- (M= Nb, Ta) perovskite powders were synthesized by sol-gel, using tartrate-precursor decomposition. The crystal structure of these materials was analyzed by X-ray powder diffraction. Rietveld refinements showed that both samples achieved the cubic crystal structure (Pm-3m), which was stabilized by the incorporation of highly-charged transition-metal cations at the octahedral sites. This synthesis method successfully lowered the calcination temperature relative to other methods mentioned in literature. The concentration of oxygen vacancies ( value) was determined by thermogravimetric analysis. Microstructural analysis revealed micrometric scale particles with a superficial nanometric dendritic array with an average grain size less than 100 nm. The present work provides a new strategy to synthesize nanostructured perovskite materials that could have better electrical and electrochemical properties.