溶胶-凝胶法制备Nd1.85Ce0.15CuO4-δ先驱体及粉体(英文)

Preparation of Nd_(1. 85)Ce_(0. 15)CuO_(4-δ) Precursor and Powders by Sol-gel Method

以柠檬酸为螯合剂,采用一种简单的溶胶-凝胶法,成功的合成了蓝色透明的Nd-Ce-Cu-O体系的凝胶,保证了各元素在分子级别的均匀混合。采用红外光谱仪、热分析和XRD对实验过程和产物进行了分析。结果表明,对干凝胶及粉体的分析结果显示金属离子与柠檬酸螯合形成金属-柠檬酸螯合物,这些螯合物又通过酯化反应相互聚合成胶体粒子。干凝胶在30～600℃的温度区间内有五个失重过程。在600℃下已经合成了Nd1.85Ce0.15CuO4-δ粉体,该合成温度远低于固相法,此外通过谢勒公式计算得在600℃、700℃和1000℃下煅烧获得的粉体的平均粒径分别是18.2nm,31.1 nm和60.5 nm。

Nd1. 85Ce0. 15CuO4-δprecursor and powders were successfully synthesized by a quite simple solgel method using citric acid（CA） as the chelating agent. The process and products were analyzed by FTIR spectra,TG and XRD. The results show that the gel transforme into porous ash-like powders after heat treating. The formation of metal-citrate coordination complex which was polymerized to colloid particles through esterification. There are five major endothermic weight losses in the temperature range of 30-600℃. The single phase Nd1. 85Ce0. 15CuO4-δpowders were synthesized at 600 ℃,which is much lower than solid state method. Estimated according to Scherrer＇s equation,the crystallite sizes are 18. 2 nm,31. 1nm and 60. 5 nm at the calcination temperatures of 600 ℃,700 ℃,and 1000 ℃,respectively. All the powders show ash-like and agglomerated.