Zhong Minglong, Liu Zhongwu, Yu Hongya, Zhong Xichun, Zeng Dechang, Ramanujan R V
School of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, PR China.
J Nanosci Nanotechnol. 2013 Feb;13(2):1525-9. doi: 10.1166/jnn.2013.5976.
Large-area one dimensional (1D) alpha-Fe2O3 nanostructures were grown on iron substrates by catalyst-free thermal oxidation process at low temperatures in air. The structure characterization revealed that the nanostructures are single crystalline alpha-Fe2O3. Two kinds of alpha-Fe2O3 nanostructures, nanobelts and nanoflakes, were obtained due to the different growth temperature range. A surface diffusion mechanism is proposed to account for the nanobelts and nanoflakes growth. The Morin temperature T(M) of pure 1D alpha-Fe2O3 nanostructures is 121 K, which is far below their bulk counterparts. The coercive field depends on temperature, and takes values 471 Oe at 5 K and about 260 Oe when the temperature is greater than T(M), respectively.
通过在空气中低温无催化剂热氧化工艺，在铁基底上生长出大面积一维（1D）α-Fe₂O₃纳米结构。结构表征显示这些纳米结构为单晶α-Fe₂O₃。由于生长温度范围不同，获得了两种α-Fe₂O₃纳米结构，即纳米带和纳米片。提出了一种表面扩散机制来解释纳米带和纳米片的生长。纯一维α-Fe₂O₃纳米结构的莫林温度T(M)为121 K，远低于其体相材料。矫顽场取决于温度，在5 K时为471 Oe，当温度高于T(M)时约为260 Oe。
