Surfactant-assisted synthesis of alpha-Fe2O3 nanotubes and nanorods with shape-dependent magnetic properties.
Alpha-Fe(2)O(3) nanorods and nanotubes have been synthesized and characterized by high-resolution transmission electron microscopy and X-ray diffraction. By means of different surfactant assistance, the high-quality one-dimensional products were obtained, respectively, with aqueous butanol solution as the solvent and carbamide as the base, giving rise to single-crystalline products at 150 degrees C. The formation mechanism has been presented. Significantly, the magnetic investigations show that the magnetic properties are strongly shape-dependent; i.e., the nanorods have a Morin transition at 166 K from canted antiferromagnetic state to antiferromagnetic state, while the nanotubes exhibit a three-dimensional magnetic ordering above 300 K that has been attributed to the presence of small particles in a few regions of the tubes.
Liu
Lu
L
Tianjin Key Laboratory of Environmental Remediation and Pollution Control, Nankai University, Tianjin 300071, China.
Kou
Hui-Zhong
HZ
Mo
Wenling
W
Liu
Huajie
H
Wang
Yuqiu
Y