Effects of Synthetic Parameters in Pechini Method on the Formation and Properties of (ZrO2)0.92(Sc2O3)0.08 Solid Solution
来源期刊：JOURNAL OF RARE EARTHS2004年第4期
论文作者：严纯华 张亚文 王晶晶 严铮光
Key words：materials chemistry; scandia stabilized zirconia; Pechini method; rare earths;
Abstract: Homogeneous (ZrO2)0.92(Sc2O3)0.08 solid solution in fluorite cubic structure was prepared from the gels with altered molar ratios of citric acid (CA) to metal ions (M) and ethylene glycol (EG) via a polymerization route (Pechini method). Due to the enhanced chemical homogeneity (high level of mixing of metal ions and ligands) in the polymeric gels, Sc-doped zirconia can be crystallized at temperatures as low as 400 ℃. During the evolution from amorphous gel to the crystallized (ZrO2)0.92(Sc2O3)0.08 fine powder, the bonding nature between carboxylate groups and Zr/Sc cations changed: unidentate→bridging→ionic upon calcination. The molar ratios of CA/M (1～4) and CA/EG (0.2～4) were demonstrated to affect the thermal behavior of the gels and thus the particle properties of the derived nanoparticulate oxide powders (including particle size and surface area). The as-sintered sample compacted from the nanosized powders prepared by calcining the gel with the highest content of organics (CA/M=4 and CA/EG=0.2) exhibited the best sinterability and the highest oxide ion conductivity.
严纯华1，张亚文1，王晶晶1，严铮光1
(1.State Key Laboratory of Rare Earth Materials Chemistry and Applications & PKU-HKU Joint Laboratory on Rare Earth Materials and Bioinorganic Chemistry,Peking University,Beijing 100871,China)
Abstract:Homogeneous (ZrO2)0.92(Sc2O3)0.08 solid solution in fluorite cubic structure was prepared from the gels with altered molar ratios of citric acid (CA) to metal ions (M) and ethylene glycol (EG) via a polymerization route (Pechini method). Due to the enhanced chemical homogeneity (high level of mixing of metal ions and ligands) in the polymeric gels, Sc-doped zirconia can be crystallized at temperatures as low as 400 ℃. During the evolution from amorphous gel to the crystallized (ZrO2)0.92(Sc2O3)0.08 fine powder, the bonding nature between carboxylate groups and Zr/Sc cations changed: unidentate→bridging→ionic upon calcination. The molar ratios of CA/M (1～4) and CA/EG (0.2～4) were demonstrated to affect the thermal behavior of the gels and thus the particle properties of the derived nanoparticulate oxide powders (including particle size and surface area). The as-sintered sample compacted from the nanosized powders prepared by calcining the gel with the highest content of organics (CA/M=4 and CA/EG=0.2) exhibited the best sinterability and the highest oxide ion conductivity.
Key words:materials chemistry; scandia stabilized zirconia; Pechini method; rare earths;
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