Investigation on Magnetic Properties of Hematite Superstructures with Controlled Microstructures
Abstract
Magnetic properties of a series of hematite particles of pseudocubic or pseudoellipsoidal shape consisting of sub-nanoparticles, as well as irregularly shaped hematite agglomerates, were investigated. The microstructures of hematite particles directly obtained from a hydrothermal process were finely controlled with different experimental conditions, such as the type of counter anion, Fe3+/OH- ratio, surfactant, and aging time. Although samples with different microstructures have a nearly same value of the saturation magnetization, a large variation in the coercivity (Hc) is observed. Hc is found to be closely related to the microcrystal size and its packing density, as well as the formed particle morphologies. The findings obtained in this work contribute to further understanding about the correlation between the microstructural features and the magnetic properties of hematite superstructures. With such fundamental knowledge, it is possible for a systematic search of controlling synthesis parameters which will further lead to the fabrication of hematite particles with optimized magnetic properties for different technological demands.References
2. Chow, H., and Keffer, F. (1974). "Soft surface magnons and the first-order magnetic phase transitions in antiferromagnetic hematite," Phys. Rev. B, 10, 243.
3. Cullity, B. D. (1978). Elements of X-Ray Diffraction. Massachusetts, Addison-
4. Wesley. Goya, G. F., Veith, M., Rapalavicuite, R., Shen, H., and Mathur, S. (2005). "Thermal hysteresis of spin reorientation at Morin transition in alkoxide derived hematite nanoparticles," Appl. Phys. A Mater. Sci. Process., 80, 1523-1526.
5. Jia, C. J., Sun, L. D., Yan, Z. G., You, L. P., Luo, F., Han, X. D., Pang, Y. C., Zhang, Z., and Yan, C. H. (2005). "Iron oxide nanotubes - Single- crystalline iron oxide nanotubes," Angew. Chem. Int. Edit., 44, 4328 – 4333.
6. Jing, Z. H., and Wu, S. H. (2004a). "Synthesis and characterization of monodisperse hematite nanoparticles modified by surfactants via hydrothermal approach," Mater. Lett., 58, 3637 – 3640.
7. Jing, Z. H., Wu, S. H., Zhang, S. M., and Huang, W. P. (2004b). "Hydrothermal fabrication of various morphological alpha-Fe2O3 nanoparticles modified by surfactants," Mater. Res. Bull., 39, 2057 – 2064.
8. Liu, X. M., Fu, S. Y., Xiao, H. M., and Huang, C. J. (2005). "Preparation and,characterization of shuttle-like alpha- Fe2O3 nanoparticles by supermolecular template," J. Solid State Chem., 178, 2798 – 2803.
9. Lu, L., Li, L. P., Wang, X. J., and Li, G. S. (2005). "Understanding of the finite size effects on lattice vibrations and electronic transitions of nano alpha- Fe2O3," J. Phys. Chem. B, 109, 17151 – 17156.
10. Ocana, M., Morales, M. P., and Serna, C. J. (1995). "The Growth- Mechanism of Alpha- Fe2O3 Ellipsoidal Particles in Solution," J. Colloid Interface Sci., 171, 85-91.
11. Ostwald, W. (1897). Z. Phys. Chem., 22, 289. Ozaki, M., Kratohvil, S., and Matijevic, E. (1984). "Formation of Monodispersed Spindle- Type Hematite Particles," J. Colloid Interface Sci., 102, 146-151.
12. Park, G. S., Shindo, D., Waseda, Y., and Sugimoto, T. (1996). "Internal structure analysis of monodispersed pseudocubic hematite particles by electron microscopy," J. Colloid Interface Sci., 177, 198-207.
13. Predoi, D., Kuncser, V., Tronc, E., Nogues, M., Russo, U., Principi, G., and Filoti, G. (2003). "Magnetic relaxation phenomena and inter- particle interactions in nanosized gamma- Fe2O3 systems," J. Phys. Condes. Matter, 15, 1797-1811.
14. Rath, C., Sahu, K. K., Kulkarni, S. D., Anand, S., Date, S. K., Das, R. P., and Mishra, N. C. (1999). "Microstructure-dependent coercivity in monodispersed hematite particles," Appl. Phys. Lett., 75, 4171- 4173. 60 Investigation on Magnetic Properties of Hematite Superstructures with Controlled Microstructures
15. Sahu, K. K., Rath, C., Mishra, N. C., Anand, S., and Das, R. P. (1997). "Microstructural and magnetic studies on hydrothermally prepared hematite," J. Colloid Interface Sci., 185, 402-410.
16. Schroeer, D., and Nininger, R. C. (1967). "Morin Transition in a-Fe2O3 microcrystals," Phys. Rev. Lett., 19, 632-634.
17. Shindo, D., Park, G. S., Waseda, Y., and Sugimoto, T. (1994). "Internal Structure- Analysis of Monodispersed Peanut- Type Hematite Particles Produced by the Gel-Sol Method," J. Colloid Interface Sci., 168, 478-484.
18. Sugimoto, T., Khan, M. M., Muramatsu, A., and Itoh, H. (1993). "Formation Mechanism of Monodisperse Peanut-Type Alpha- Fe2O3 Particles from Condensed Ferric Hydroxide Gel," Colloid Surf. A- Physicochem. Eng. Asp., 79, 233-247.
19. Sugimoto, T., Muramatsu, A., Sakata, K., and Shindo, D. (1993). "Characterization of Hematite Particles of Different Shapes," J. Colloid Interface Sci., 158, 420-428.
20. Tang, B., Wang, G. L., Zhuo, L. H., Ge, J. C., and Cui, L. J. (2006). "Facile route to alpha- FeOOH and alpha-Fe2O3 nanorods and magnetic property of alpha- Fe2O3 nanorods," Inorg. Chem., 45, 5196-5200.
21. Vayssieres, L., Sathe, C., Butorin, S. M., Shuh, D. K., Nordgren, J., and Guo, J. H. (2005). "One-dimensional quantum- confinement effect in alpha- Fe2O3 ultrafine nanorod arrays," Adv. Mater., 17, 2320- 2324.
22. Woo, K., Lee, H. J., Ahn, J. P., and Park, Y. S. (2003). "Sol-gel mediated synthesis of Fe2O3 nanorods," Adv. Mater., 15, 1761- 1765.
23. Xu, R., and Zeng, H. C. (2004). "Self- generation of tiered surfactant superstructures for one-pot synthesis of Co3O4 nanocubes and their closeand non-close-packed organizations," Langmuir, 20, 9780- 9790.
24. Zhu, L. P., Xiao, H. M., and Fu, S. Y. (2007). "Template-free synthesis of monodispersed and single- crystalline cantaloupe-like Fe2O3 superstructures," Cryst. Growth Des., 7, 177-182.
25. Zhu, L. P., Xiao, H. M., Liu, X. M., and Fu, S. Y. (2006). "Template-free synthesis and characterization of novel 3D urchin-like alpha-Fe2O3 superstructures," J. Mater. Chem., 16, 1794-1797.
Copyright holder for articles is ASEAN Journal of Chemical Engineering. Articles published in ASEAN J. Chem. Eng. are distributed under a Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) license.
Authors agree to transfer all copyright rights in and to the above work to the ASEAN Journal of Chemical Engineering Editorial Board so that the Editorial Board shall have the right to publish the work for non-profit use in any media or form. In return, authors retain: (1) all proprietary rights other than copyright; (2) re-use of all or part of the above paper in their other work; (3) right to reproduce or authorize others to reproduce the above paper for authors’ personal use or for company use if the source and the journal copyright notice is indicated, and if the reproduction is not made for the purpose of sale.