Thermal Growth and Nanomagnetism of the Quasi-one Dimensional Iron Oxide  

作　　者：Minglong Zhong Zhongwu Liu Xichun Zhong Hongya Yu Dechang Zeng 

机构地区：[1]School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, China

出　　处：《Journal of Materials Science & Technology》2011年第11期985-990,共6页材料科学技术（英文版）

基　　金：supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China, the Natural Science Foundation of China (Grant Nos. U0734001, 50874050);the Fundamental Research Funds for the Central Universities, SCUT (Grant No. 2009ZZ0025)

摘　　要：Quasi-one dimensional iron oxide nanowires with flat needle shape were synthesized on the iron powders by a rather simple catalyst-free thermal oxidation process in ambient atmosphere. The characterization by field emission scanning electron microscopy （FE-SEM）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, Raman and high-resolution transmission electron microscopy （HRTEM） revealed that these nanos- tructures are single crystalline α-Fe2O3. The various dimensions with 40-170 nm in width and 1-8 μm in length were obtained by tuning the growth temperature from 280 to 480℃. A surface diffusion mechanism was proposed to account for the growth of quasi-one dimensional nanostructure. The typical α-Fe203 nanowires synthesized at 430℃ had a reduced Morin temperature TM of 131 K in comparison with their bulk counterpart. The coercivitis Hc of these nanowires are 321 and 65 Oe at 5 and 300 K, respectively. The temperature of synthesis also has important effects on the magnetic properties of these nanowires.Quasi-one dimensional iron oxide nanowires with flat needle shape were synthesized on the iron powders by a rather simple catalyst-free thermal oxidation process in ambient atmosphere. The characterization by field emission scanning electron microscopy （FE-SEM）, X-ray photoelectron spectroscopy （XPS）, X-ray diffraction （XRD）, Raman and high-resolution transmission electron microscopy （HRTEM） revealed that these nanos- tructures are single crystalline α-Fe2O3. The various dimensions with 40-170 nm in width and 1-8 μm in length were obtained by tuning the growth temperature from 280 to 480℃. A surface diffusion mechanism was proposed to account for the growth of quasi-one dimensional nanostructure. The typical α-Fe203 nanowires synthesized at 430℃ had a reduced Morin temperature TM of 131 K in comparison with their bulk counterpart. The coercivitis Hc of these nanowires are 321 and 65 Oe at 5 and 300 K, respectively. The temperature of synthesis also has important effects on the magnetic properties of these nanowires.

关 键 词：Thermal growth One-dimensional nanostructures Iron oxide Magnetic materials 

分 类 号：TB[一般工业技术]