采用分析纯CoCl2·6H2O、ZnCl2·6H2O、FeCl3·6H2O和NaOH为主要原料,控制反应物摩尔比,利用低温固相反应法制备了尖晶石型CoFe2O4、ZnFe2O4和Co0.5Zn0.5Fe2O4纳米粒子。采用X射线衍射、透射电子显微镜对样品的结构、形貌进行表征。在室温下采用振动样品磁强计对其磁性能进行了测定。结果表明:反尖晶石型CoFe2O4纳米粒子的饱和磁化强度为64.28A·m^2/kg,呈亚铁磁性;正尖晶石型ZnFe2O4纳米粒子的饱和磁化强度为7.27A·m^2/kg,表现出与块体的反铁磁性不同的超顺磁性;而Zn^2+替代反尖晶石型CoFe2O4中的一部分磁性离子Co^2+形成的复合铁氧体Co0.5Zn0.5Fe2O4的饱和磁化强度为35.06A·m^2/kg,呈亚铁磁性。最后,对3种铁氧体的磁性来源进行了探究。
Spinel-type CoFe2O4, ZnFe2 O4 and Co0.5 Zn0.5 Fe2O4 nanoparticles were prepared by low-temperature solid state method using CoCl2 · 6H2O, ZnCl2 · 6H2O, FeCl3 - 6H2O and NaOH as reactants, and the molar ratio of reactants was controlled. The crystal structure and shape were characterized by XRD and TEM. The magnetic properties of the powders were measured using vibrating sample magnetometer at room temperature. The saturated magnetization of inverse spinel-type CoFe2O4 nanoparticles was 64.28A · m^2/kg, exhibiting subferromagnetism. The saturated magnetization of positive spinel-type ZnFe204 nanoparticles was 7. 27A · m^2/ kg, exhibiting superparamagnetism different from antiferromagnetism of the block. If the partial cations Co^2+ of the inverse ferrite CoFe2O4 was substituted by Zn^2+ , the complex ferrite Co0.5Zr0.5Fe2O4 was formed, and its saturated magnetization was 35.06A · m^2/kg, exhibiting subferromagnetism. Finally, the magnetism origin of the above outlined ferrite was investigated.