Zn_xFe_(3-x)_O_4磁性液体的制备及性能研究

Preparation and magnetic properties of Zn_xFe_(3-x)O_4 magnetic fluids

利用改进的化学共沉淀法制备ZnxFe3-xO4(x＝0.1～0.3)纳米颗粒,研究了Z2+n的摩尔比对ZnxFe3-xO4纳米颗粒比饱和磁化强度的影响;选择饱和磁化强度最大的Zn0.2Fe2.8O4纳米粉体,制备了煤油基磁性液体,对其饱和磁化强度、黏度等性质进行研究;结果表明:当x为0.2时,饱和磁化强度达到最大,为63.07Am2/kg;合成的磁性液体在外磁场作用下显出超顺磁性,其比饱和磁化强度随密度的增大而增大,最大可达29.93 Am2/kg;随着温度的升高,磁性液体的黏度下降,质量浓度越大,其下降速度越快,在30℃时,当质量浓度小于0.28g/mL时,磁性液体呈现牛顿流体特性,当质量浓度大于0.28g/mL时,牛顿流体特性消失.

ZnxFe3-xO4（x=0.1-0.3） nanoparticles were synthesized by the modified chemical coprecipitation method ,and the influence of the content of Zn^2＋ on the specific saturation magnetization and its mechanism were studied. Then a series of magnetic fluids were prepared using the Zn0.2Fe2.8O4 nanoparticles and their magnetic and viscosity properties were also investigated. The results show that when the content of Zn^2＋ is 0.2 ,the specific saturation magnetization of the ZnxFe3-xO4 nanoparticles is biggest ,which is 63.07 Am^2/kg. The magnetic fluids show superparamagnetism in the applied magnetic field and the specific saturation magnetization increases with the increasing of density ,and the utmost value is up to 29. 93 Am^2/kg. The viscosity decreases with the rising of temperature,and at 30℃ ,when the mass percentage is smaller than 0.28 g/mL,the magnetic fluids are Newtonion fluids,but when the mass percentage is bigger than 0.28 g/mL,the fluids lose the Newtonian property.