水热法制备核壳结构Sm(Co,Hf)_7@Fe_3O_4复合纳米颗粒及其磁性能研究  

Study on the preparation and magnetic properties of Sm(Co,Hf)_7@Fe_3O_4 nanocomposite particles with core-shell structure by hydrothermal method

作　　者：步绍静[1] 赵玉霞[1] 张志清 孙继兵[1] 李丹[1] 

机构地区：[1]河北工业大学河北省新型功能材料重点实验室,天津300130 [2]河北省金科冶金研究院有限责任公司,河北石家庄050031

出　　处：《河北工业大学学报》2014年第4期26-32,共7页Journal of Hebei University of Technology

基　　金：国家自然科学基金(51271072);国家自然科学青年基金(51301056);河北省高等学校科学技术研究重点项目(ZH2011202);河北省自然科学青年基金(E2013202030)

摘　　要：以高能球磨所得Sm Co,Hf7纳米颗粒作为硬磁性内核,通过水热法在其上包覆软磁性Fe3O4壳层,制备了具有核壳结构的Sm Co,Hf7@Fe3O4硬/软耦合纳米颗粒.利用XRD、TEM、VSM等检测手段分析了纳米颗粒的相结构、微观结构及磁性能.结果显示,所得Sm Co,Hf7@Fe3O4复合纳米颗粒呈现明显的核壳型结构,颗粒粒度均匀且分散性良好,Fe3O4壳层的厚度在5 nm左右.磁性能测试表明,Fe3O4软磁壳层的包覆使复合颗粒的矫顽力和剩磁比与纯Sm Co,Hf7颗粒相比有所下降.对复合颗粒在660℃进行退火处理30 min,发现在加热过程中核壳之间将发生元素的互扩散并进而形成梯度型微观结构.Core-shell structured Sm（Co, Hf）7@Fe3O4 hard/soft magnetic Sin（Co, Hf）7 nanoparticles with soft magnetic Fe304 coupling nanoparticles were prepared by encapsulating hard shells via hydrothermal method, in which the Sm（Co, Hf）7 particles were obtained by high-energy bail-milling technique. The phase structure, microstructure and magnetic properties of particles were analyzed by means ofXRD, TEM and VSM. The results show that the obtained Sin（Co, HO7@Fe3O4 composite particles exhibit an obvious core-shell structure with the shell thickness of 5 nm. The particle size is homogene- ous and the dispersity is good. Magnetic tests demonstrate that the coating of Fe304 shell leads to a decrease in the coer- civity and remanence ratio of composite particles. During the annealing of composite nanoparticles at 660 ℃ for 30 min, element inter-diffusion between core and shell may occur, resuting in a gradient-type microstructure.

关 键 词：磁性材料 核壳结构 水热法 微结构 磁性能 

分 类 号：TM273[一般工业技术—材料科学与工程]