中文摘要：

采用化学共沉淀的方法制备了20nm粒径的Fe3O4颗粒，颗粒具有很好的尖晶石结构，其晶格常数比块材料略小；磁性测量表明了其具有良好的亚铁磁性。重点研究了由Fe3O4纳米颗粒制成的磁性液体在频率为72kHz的交变磁场下的磁感应发热行为，并对于磁场、磁性液体的浓度、载液的种类等因素对磁感应发热的饱和温度和升温速率的影响进行了测量和分析，进一步理解了磁感应发热的机制。

英文摘要：

The magnetic induction heating behaviors of magnetic liquid with magnetite nano - particles under the AC magnetic field with the frequency of 72 kHz was studied. The magnetite nano - particles with the size of 20 nm were synthesized by the chemical coprecipitation method. The particles had a well defined cubic spinel structure and the lattice constant were less than that in bulk material. The magnetite particles were shown good ferrimagnetism, The effect of strength of magnetic field, concentration of magnetite particles in magnetic liquid and carrying liquid on dwell temperature of magnetic induction heating was measured and analyzed. The mechanism of magnetic induction heating was discussed.