Morphology and magnetic properties of α-Fe_2O_3 particles prepared by octadecylamine-assisted hydrothermal method  

作　　者：Zhong Liu Baoliang Lv Dong Wu Yuhan Sun 

机构地区：[1]State Key Laboratory of Coal Conversion,Institute of Coal Chemistry,Chinese Academy of Sciences,Taiyuan 030001,China [2]Low Carbon Conversion Center,Shanghai Advanced Research Institute,Chinese Academy of Sdences,Shanghai 201203,China [3]Graduate University of the Chinese Academy of:Sciences,Beijing 100049,China

出　　处：《Particuology》2012年第4期456-461,共6页颗粒学报（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 21003147);Natural Science Foundation of Shanxi (2011011007-3);Distinguished Young Scholar Project of Institute of Coal Chemistry, Chinese Academy of Sciences (2011SJCRC07);the State Key Laboratory of Coal Conversion(SKLCC) In-house Project (No. 2011BWZ005)

摘　　要：α-Fe2O3 particles with various morphologies, including micro-doublesphere, tetrakaidecahedron and nanoparticles-aggregated micro-ellipsoid, were successfully synthesized via an octadecylamine-assisted hydrothermal method. The products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and high-resolution transmission electron microscopy （HRTEM）. The results indicate that the presence of octadecylamine played a crucial role in morphology evolution by selective crystal adsorption. The protonated octadecylamine increased the pH value that accelerated nucleation, and the long alkyl groups of octadecylamine acted as an adsorption inhibitor to retard the growth of nanoparticles. The as-prepared α-Fe2O3 particles exhibited higher remanent magnetization and coercivity than other α-Fe2O3 particles of similar size. These properties should be attributed to the superstructure and the shape anisotropy of the synthesized particles.α-Fe2O3 particles with various morphologies, including micro-doublesphere, tetrakaidecahedron and nanoparticles-aggregated micro-ellipsoid, were successfully synthesized via an octadecylamine-assisted hydrothermal method. The products were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and high-resolution transmission electron microscopy （HRTEM）. The results indicate that the presence of octadecylamine played a crucial role in morphology evolution by selective crystal adsorption. The protonated octadecylamine increased the pH value that accelerated nucleation, and the long alkyl groups of octadecylamine acted as an adsorption inhibitor to retard the growth of nanoparticles. The as-prepared α-Fe2O3 particles exhibited higher remanent magnetization and coercivity than other α-Fe2O3 particles of similar size. These properties should be attributed to the superstructure and the shape anisotropy of the synthesized particles.

关 键 词：Octadecylaminec α-Fe2O3MorphologiesMagnetic property 

分 类 号：TB383[一般工业技术—材料科学与工程] TQ172.16[化学工程—水泥工业]