溶胶-凝胶自燃烧法制备纳米CoYxFe2-xO4铁氧体的特性

采用溶胶-凝胶自燃烧法制备了CoYxFe2-xO4(x=0.0,0.1,0.2,0.3)铁氧体纳米粉末,并在不同温度下对样品进行了热处理.利用热重/差热综合分析仪及Fourier变换红外光谱仪研究样品的热反应过程.利用X射线衍射仪和振动样品磁强计对样品的结构、晶粒尺寸和磁性进行了测量和分析.结果表明:经自燃烧和不同温度热处理后粉末样品都具有尖晶石结构,晶粒尺寸为10～22 nm之间,存在亚铁磁性.随着稀土钇掺杂量的增加,晶格常数呈现变小趋势,晶粒尺寸减小,矫顽力增大,比饱和磁化强度减小,样品形成单相尖晶石结构能力变弱.经过热处理后,样品的晶格常数、晶粒尺寸、比饱和磁化强度增加,而矫顽力先增后减.

CHARACTERISTICS OF CoYxFe2-xO4 FERRITE POWDERS SYNTHESIZED BY SOL-GEL SELF-COMBUSTION

CoYxFe2-xO4(x=0,0.1,0.2,0.3)ferrite powders were synthesized by the sol-gel self-combustion method.The thermal reaction process of amorphous gelatin was studied by thermogravimetric-differential thermal analysis and Fourier transform infrared spectrometry.The structure,crystallite size and magnetic properties of powders were investigated by X-ray diffraction and vibrating sample magne-tometer.The results indicate that a single-spinel phase powder with a grain size between 10 and 22 nm is formed after self-combustion synthesis or heat treatment.With the gradual increase in rare-earth Y content,the lattice constants,the size and saturation magnetization of the particles decrease,and the coercivity increases for the samples after self-combustion synthesis.After the heat treatment,the lattice con-stants,the size and saturation magnetization of the particles increase,and the coercivity first increases and then decreases.