热处理工艺对共沉淀CoFe_2O_4纳米颗粒的缺陷和磁性能的影响

Effects of Annealing Temperature on Defects and Magnetic Properties of CoFe_2O_4 Nanoparticles Synthesized by Co-precipitation Method

通过化学共沉淀法制备了CoFe2O4纳米颗粒,并在不同的温度下进行热处理,研究了不同热处理工艺对CoFe2O4纳米颗粒的缺陷与磁性能的影响。X射线衍射谱(XRD)显示所有样品具有单一的尖晶石铁氧体结构,振动样品磁强计(VSM)测试显示了所有样品典型的铁磁性特征。红外光谱(FT-IR)显示650℃及以下温度热处理的样品存在较多的金属氢氧基缺陷,而在更高热处理温度时缺陷即可去除。化学共沉淀法制备的CoFe2O4纳米颗粒在不同的热处理温度时,晶粒尺寸与金属氢氧基缺陷共同导致了磁性能的变化。

Cobalt ferrite（CoFe2O4） nanoparticles have been synthesized by a chemical co-precipitation method and annealed at different temperatures.Effects of annealing temperature on defects and magnetic properties of CoFe2O4 nanoparticles have been studied and discussed.X-ray diffraction（XRD） patterns show that all the samples are spinel structure.Vibrating sample magnetometer（VSM） tests show that all the samples are ferromagnetic.Fourier transform infrared spectroscopy（FT-IR） curves show that samples annealed below 650°C have metal-hydroxyl defects which can be removed at higher annealing temperature.For CoFe2O4 nanoparticles synthesized by co-precipitation method,changes of magnetic properties are resulted by grain size and metal-hydroxyl defects at different annealing temperature.