Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1556352 | Journal of Materials Science & Technology | 2011 | 6 Pages |
Abstract
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°C. A surface diffusion mechanism was proposed to account for the growth of quasi-one dimensional nanostructure. The typical α-Fe2O3 nanowires synthesized at 430°C 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.
Related Topics
Physical Sciences and Engineering
Materials Science
Materials Chemistry
Authors
Minglong Zhong, Zhongwu Liu, Xichun Zhong, Hongya Yu, Dechang Zeng,