Fe_3O_4纳米颗粒的磁后效研究  

Studies on Magnetic Aftereffect of Fe_3O_4 Nano-particles

作　　者：李凤舞[1] 

机构地区：[1]燕山大学继续教育学院,秦皇岛066004

出　　处：《信息记录材料》2007年第4期45-48,共4页Information Recording Materials

摘　　要：用Preisach磁滞模型模拟了Fe3O4纳米颗粒的磁后效行为,并与实验测量结果进行了比较。结果表明:理论计算和实验结果符合的较好。其磁化强度随时间单调减小,与时间的对数成线性变化,磁场越接近负的矫顽力时衰减越快。通过Preisach模拟得到体系的涨落场和激活体积,激活体积大于实验测得的平均颗粒尺寸,由此解释了Fe3O4纳米颗粒的反磁化机制。The magnetic aftereffects of nano-particle were simulated by Preisach hysteresis model, the results showed excellent agreement with the experiment measurement. Magnetization decay followed typical logarithmic time dependence. The decay occured more rapidly for field closer to the coericivity. Thermal fluctuation field and the activation volume were obtained from Preisach modeling. The activation volume was larger than the mean particle size and the reverse magnetization mechanism was deduced.

关 键 词：PREISACH模型 磁后效 热涨落场 激活体积 

分 类 号：TQ314.245[化学工程—高聚物工业]