材料期刊网

为了改善NiFe_2O_4纳米粉体气敏性,采用低温固相反应法制备了不同形貌的NiFe_2O_4纳米粉体.以FeSO_4·7H_2O、NiSO_4·6H_2O和NaOH作为反应物,充分研磨制备前驱体,通过先抽滤后600℃热处理和先600℃热处理后抽滤制备了两种NiFe_2O_4纳米粉体,通过X射线衍射和扫描电镜考察了不同制备工艺对纳米晶粒尺寸及形貌的影响.XRD和SEM分析结果表明:两种制备工艺均能生成NiFe_2O_4尖晶石相.先抽滤后热处理制备的NiFe_2O_4纳米粉体颗粒尺寸约为80 nm,颗粒呈立方体结构.而先热处理后抽滤制备的NiFe_2O_4纳米粉体,由于热处理过程中存在Na_2SO_4相,使得NiFe_2O_4纳米粉体颗粒呈圆形片状结构分布,颗粒尺寸为50 nm,厚度约10 nm.

In order to improve the gas sensitivity of NiFe_2O_4 nano-particles, NiFe_2O_4 nano-particles with dif-ferent morphologies were perpared by low-temperature solid-state reaction technique. The precursor powder was prepared by rubbing FeSO_4·7H_2O, NiSO_4·6H_2O and NaOH sufficiently. Two kinds of NiFe_2O_4 nano-particles were prepared by dealing with the precursor powder through pumping and filtrating first and then heat treating at 600 ℃, and heat treating at 600 ℃ first and then pumping and filtrating, respectively. Influences of the two preparation processes on particle size and morphology were investigated by XRD and SEM. Results show that the nano-powders prepared by the two methods are both with NiFe_2O_4 spinel phase. The particle size of NiFe_2O_4 spinel prepared by the first process is about 80 nm, and the particle morphology is cubic. While for the nanosize NiFe_2O_4 spinel particles prepared by the second process, the nanocrystal morphology is plate-like, the particle size is about 50 nm, and the thickness is about 10 nm, because of the action of Na_2SO_4phase during the heat treatment.