Abstract: Assembled nano-flake CoFe₂O₄ microspheres were synthesized by using the ultrasonic solvothermal method. The microstructure and morphology of the samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The prepared CoFe₂O₄ microspheres assembled by two-dimensional sheet were cubic structure with particle size about 20—30μm. The magnetic properties and microwave absorbing properties of the flake self-assembled CoFe₂O₄ microspheres and self-made CoFe₂O₄ powder were characterized by using vibrating sample magnetometer (VSM) and network vector analyzer. The saturation magnetization and coercive force of the flake self-assembled CoFe₂O₄ microspheres reached 76.15emu/g and 227.89Oe, respectively. In addition, the flake self-assembled CoFe₂O₄ microspheres had an obvious absorption peak at 6000MHz frequency band, where return loss value was greater than -18 dB and tended to increase. Structure and morphology of the samples had significant impact on their magnetic properties and microwave absorbing properties.

Key words: flake self-assembled, cobalt ferrite, ultrasonic solvothermal method, magnetic properties, microwave absorbing properties

摘要： 采用超声溶剂热法,成功地制备了由片状钴铁氧体(CoFe₂O₄)自组装的微球。采用X射线衍射仪(XRD)、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CoFe₂O₄微球为立方晶相结构,其粒径分布在20～30μm之间,是由二维纳米片组装而成。用振动样品磁强计(VSM)和网络矢量分析仪分别对纳米片组装微球样品及自制的CoFe₂O₄粉体的室温磁性和吸波性能进行了测试,结果显示,纳米片组装微球比自制粉体的磁性和微波吸收性能更好,其饱和磁化强度和矫顽力分别达到76.15emu/g和227.89Oe。此外,纳米片组装CoFe₂O₄微球在频率为6000MHz波段附近有一个明显的吸收峰,回损值大于-18dB,并有继续增大的趋势。说明产物的结构和形貌对其磁性和吸波性都有很大影响。

关键词: 片状组装, 钴铁氧体, 超声溶剂热法, 磁性, 吸波性