X型六角晶系钡铁氧体纳米晶的制备和表征

用硬脂酸凝胶法制备了Co₂-X型六角晶系钡铁氧体纳米晶,在750℃热处理得到的纳米晶形貌为球形,粒径范围为15～25nm.随着热处理温度的升高,粒子逐渐长大并呈块状.振荡样品磁强计测试结果表明,Co₂-X型六角晶系钡铁氧体纳米晶具有与常规体材料不同的磁性能,其比饱和磁化强度σ_s低于后者.产物的矫顽力、比饱和磁化强度随粒子的长大呈规律性的变化.

Synthesis and Characterization of X-type Barium Ferrite Nanocrystals

Nanostructured samples of X-type Ba₂Co₂Fe₂₈O₄₆ hexagonal ferrite have been prepared by using the stearic acid gel method. The nanocrystalline hexaferrite powders obtained at 750 ℃ were spherical in shape with grain sizes in the range of 15～25 nm. With increasing calcining temperature, the particles become a plate-like structure. The magnetic properties of Xtype barium ferrite nanocrystals were measured by using Vibrating Sample Magnetometer(VSM). The results indicate that the magnetic properties of the title products are different from those of the common X-type hexaferrites with a lower specific saturation magnetization( σ_s). Coercivity force( H_c) and the specific saturation magnetization( σ_s) of the products are influenced by the particles sizes.