The mono-dispersed superparamagnetic CoFe₂O₄ nanoparticles have been prepared by polyol method at different synthesis conditions. The Raman results clearly emphasize that the samples prepared for 3 h reaction time alone have the peaks corresponding to pure CoFe₂O_4. The percentage of iron content was found to be high for sample prepared for 6 h (72.2%) reaction time compared to sample prepared for 12 h (65.4%). The atomic ratio between Co²⁺ and Fe³⁺ for samples prepared in 12 h reaction time is closer to 0.5 as expected from the CoFe₂O₄ stoichiometry but VSM data shows that sample prepared for 12 h reaction time have low magnetic saturation value. The increase of cobalt content and decrease of saturation value clearly emphasize that some changes have been occurred. Herein, we analyze and propose the possible reaction mechanism that could be occurred in different reaction time and thereby influencing the magnetic properties of the nanoparticles.

通过多元醇法在不同的合成条件下制备了单分散超顺磁性CoFe ₂ O ₄纳米颗粒。拉曼结果清楚地表明，仅在3小时的反应时间内制备的样品具有对应于纯CoFe ₂ O ₄的峰。发现与在6小时的反应时间内制备的样品相比，铁含量的百分比较高（72.2％）。样品准备12小时（65.4％）。正如在CoFe ₂ O _4中预期的那样，在12 h反应时间内制备的样品中Co ²⁺和Fe ³⁺之间的原子比接近0.5。化学计量学，但VSM数据表明，反应时间为12 h的样品制备的磁饱和值低。钴含量的增加和饱和度值的降低清楚地表明已经发生了一些变化。本文中，我们分析并提出了可能在不同反应时间内发生的反应机理，从而影响了纳米粒子的磁性能。