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采用草酸共沉淀法制备YBCO粉末,计算了不同pH值下草酸盐共沉淀粉末的沉淀率,并对制取YBCO前驱体粉末过程中的Ba(NO3)2-Y(NO3)3-Cu(NO3)2-H2C2O4-H2O体系进行热力学分析,采用XRD对制备的YBCO进行了分析计算。结果表明:溶液中不同草酸根离子浓度下各离子沉淀完全的最佳pH范围不同,当草酸浓度为0.1 mol·L-1,pH为2~6时,溶液中离子的沉淀率达到99%以上。随着草酸根离子浓度增大,完全沉淀时,共沉淀液中各金属离子所需的pH值范围增大。热力学计算与试验结果吻合。草酸共沉淀法制备的YBCO粉末物相纯度高,杂质少,颗粒细小,平均粒径为35.4 nm。
YBCO powder was prepared by oxalic acid coprecipitation method. The precipitation rate of oxalate coprecipitated powder was calculated under different pH values. The effects of Ba (NO3) 2-Y (NO3) 3-Cu (NO3 ) 2-H2C2O4-H2O system, the YBCO prepared by XRD was analyzed and calculated. The results showed that the optimum pH range of each ion precipitation was different under different concentrations of oxalate ions in the solution. When the concentration of oxalic acid was 0.1 mol·L-1 and the pH was 2 ~ 6, the precipitation rate of the ions in the solution was over 99% . As the concentration of oxalate ions increases, the pH range required for each metal ion in the coprecipitation solution increases when completely precipitated. The thermodynamic calculation is consistent with the experimental results. The YBCO powder prepared by oxalic acid coprecipitation method has the advantages of high purity, less impurities and fine particles with an average particle size of 35.4 nm.