微波固相法制备纳米镧锶镍复合氧化物

摘要

Precursor of La-Sr-Ni complex oxides nanometer powder was synthesized by solid-state reation under microwave by using La(NO3)3·6H2O、Sr(CH3COO)2·1/2H2O、Nr(CH3COO)2H2O.rnExperimental result indicates that diameter of the product is greatly affected by the decomposing temperature.The optimum conditions for preparation of the nanograde powder are microwave power=600W.decomposing temperature=600℃ and decomposing time=5h.XRD and TEM studies show that the main product phase is La0.9Sr0.1NiO3,the crystal form is rhombohedral,the space group is R-3c,and the average particle size is 10～25nm.Besides,the thermal decomposition mechanical function of precursor was obtained from analysis of DSC-TG curves.The function form of first stage is [-ln(1-α)]7/12,the function form of second stage is [-ln(1-α)]4/9.%以硝酸镧、乙酸锶和乙酸镍为原料,应用微波固相法制备了纳米镧锶镍复合氧化物前驱体.研究表明:控制热分解温度是制备超微纳米粒子的关键.最小粒径产物的制备条件是:微波炉加热功率600W,马弗炉热分解温度600℃,热分解时间5h.XRD和TEM分析结果表明,产物主要物相组成为La0.9Sr0.1NiO3属钙钛矿相斜方六面体结构,空间群R-3c,平均粒径10～25nm.应用DSC-TG技术对纳米镧锶镍复合氧化物前驱物热分解机理进行了初步探索,得两阶段分解机理函数为G(a)=[-ln(1-α)]7/12,G(a)=[-ln(1-α)]4/9.