溶剂热法合成纳米结构四氧化三铁空心微球磁性研究  

Magnetic Properties of Nano-structure Fe_3O_4 Hollow Microspheres by Solvothermal Method

作　　者：吕庆荣[1] 方庆清[1] 刘艳美[1] 

机构地区：[1]安徽大学物理与材料科学学院,安徽省信息材料与器件重点实验室,合肥230039

出　　处：《人工晶体学报》2011年第6期1557-1562,共6页Journal of Synthetic Crystals

基　　金：安徽省自然科学基金(090414177)资助项目;安徽大学博士科研启动经费资助项目

摘　　要：通过溶剂热反应合成了Fe3O4空心微球。采用X射线衍射仪(XRD)、透射电子显微镜(TEM)和扫描电子显微镜(SEM)对样品的结构和形貌进行了表征。结果表明,所制备的单分散Fe3O4空心微球为立方多晶结构,其直径约400 nm,是由约40 nm纳米颗粒组装而成。用振动样品磁强计(VSM)测量了Fe3O4空心微球的室温和变温磁性。室温磁滞回线表明不同反应时间所得产物均表现为良好的亚铁磁性,其饱和磁化强度Ms随反应时间的增加先升后降。由反应时间为12 h所得的Fe3O4空心微球在1000 Oe下的M-T曲线测得其居里温度为778 K,并测得其在外磁场H=5000 Oe场冷却至液氮温度再升至不同温度(100 K,200 K,300 K)时的磁滞回线,发现不同温度时测得的Fe3O4空心微球磁滞回线都是左右对称的,没有明显的交换偏置效应,且随测量温度增加,其饱和磁化强度Ms和矫顽力Hc均降低。Fe3O4 hollow microspheres were synthesized by solvothermal method. The structure ofsynthesized products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and transmission electron microscopy （TEM）. The results showed that monodisperse Fe3O4 hollow microspheres with polycrystal structure are assembled by nanoparticles, and their average diameteris about 400 nm. The magnetic properties were evaluated by a vibrating sample magnetometer （VSM）. The results at room temperature indicate as-prepared Fe3O4 hollow microspheres exhibit a ferromagnetic behavior, the saturation magnetization （Ms ） first increases then decreases as the reaction timeincreasing. The results at different temperature indicate the saturation magnetization （Ms） and coercivity （Ho） of Fe3O4 hollow micropheres for 12 h decreased as the measure temperature increasing, and thehysteresis loops at different temperature are all symmetrical. The cruie temperature of Fe3O4 hollow micropheres for 12 h is about 778 K according to M-T curves at 1000 Oe.

关 键 词：磁性 纳米结构 四氧化三铁 空心微球 溶剂热法 

分 类 号：TQ138.1[化学工程—无机化工]