Nano-dispersed yttria-stabilized zirconia powder: Phase, morphology, and conductivity investigation with different chelating agents via a modified sol-gel method

Abstract

8 mol% yttria-stabilized zirconia nano-powders were synthesized via a novel sol–gel method employing basic zirconium carbonate, acetic acid, and different chelating agents (citric acid, oxalic acid, and ethylenediaminetetraacetic acid (EDTA)). The dried gel and calcined nano-powders were characterized using various techniques to investigate their thermal behavior, phase composition, particle size, microstructure morphology, and electrochemical performance. It was found that the dried gel had different polymeric network structures based on the different molecular structures, number of functional groups, and acidity of the chelating agents, which led to different properties after calcination. The smallest particle size, best dispersion, and narrowest grain size distribution were obtained for the EDTA sample after calcination at 600 °C, which are attributed to the unique functional groups in EDTA. The highest relative density and smallest grain size of the EDTA sample, which resulted in enhanced grain boundary contribution and effective conducting area, led to increased ionic conductivity (0.06 S cm−1).