【摘要】 采用sol-gel法及经空气中热处理制备了CoFe2O4和CoFe2O4/SiO2纳米材料。利用XRD、SEM和振动样品磁强计(VSM)对样品的结构、晶粒尺寸及磁性能进行了研究。结果表明:SiO2的加入有助于降低CoFe2O4的形成温度,有效抑制CoFe2O4晶粒的长大,并使CoFe2O4的Hc提高。经900℃热处理的CoFe2O4/SiO2样品中已不存在杂相Fe2O3;CoFe2O4的晶粒尺寸从无SiO2时的78nm减小到15nm;样品的Hc由41.1kA·m–1提高到73.1kA·m–1。更多还原

【Abstract】 Nanosized CoFe2O4 and CoFe2O4/SiO2 were prepared by sol-gel method and heat treatment in air. The structure, grain size and magnetic properties of the samples were investigated with X-ray diffraction (XRD), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Results show that the addition of SiO2 reduces the formation temperature of CoFe2O4 and suppresses grain growth effectively, and increases the Hc of CoFe2O4. Fe2O3 phase disappeares in CoFe2O4/SiO2 sample heat-treated at 900 ℃, and the grain size of CoFe2O4 decreases from 78 nm to 15 nm, while Hc increases from 41.1 kA·m–1 to 73.1 kA·m–1 compared to the sample without SiO2 addition.更多还原