Singh Satyendra, Krupanidhi S B
Materials Research Center, Indian Institute of Science, Bangalore 560012, India.
J Nanosci Nanotechnol. 2008 Jan;8(1):335-9.
Multiferroic BiFeO3 (BFO) nanotubes have been successfully fabricated by the modified sol-gel method within the nanochannels of porous anodic aluminum oxide (AAO) templates. The morphology, structure and composition of the nanotubes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM), selected-area electron diffraction (SAED), high resolution TEM, (HRTEM) and energy-dispersive X-ray spectroscopy (EDX). Postannealed (650 degrees C for 1 h), BFO nanotubes were polycrystalline and X-ray diffraction study revealed that they are of the rhomohedrally distorted perovskite crystal structure. The results of SEM and TEM revealed that BFO nanotubes possessed a uniform length (up to 60 microm) and diameter (about 200 nm), which were controlled by the thickness and the pore diameter of the applied AAO template, respectively and the thickness of the wall of the BFO nanotube was about 15 nm. Y-junctions in the BFO nanotubes were observed. EDX analysis demonstrated that stoichiometric BiFeO3 was formed. HRTEM analysis confirmed that the obtained BFO nanotubes made up of nanoparticles (3-6 nm). The possible formation mechanism of BFO nanotubes was discussed.
通过改进的溶胶-凝胶法，在多孔阳极氧化铝（AAO）模板的纳米通道内成功制备了多铁性BiFeO3（BFO）纳米管。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、选区电子衍射（SAED）、高分辨率TEM（HRTEM）和能量色散X射线光谱（EDX）对纳米管的形貌、结构和组成进行了表征。经过650℃退火1小时后，BFO纳米管为多晶，X射线衍射研究表明它们具有菱面体畸变的钙钛矿晶体结构。SEM和TEM结果表明，BFO纳米管具有均匀的长度（可达60微米）和直径（约200纳米），分别由所用AAO模板的厚度和孔径控制，BFO纳米管的管壁厚度约为15纳米。观察到BFO纳米管中有Y形结。EDX分析表明形成了化学计量比的BiFeO3。HRTEM分析证实，所制备的BFO纳米管由纳米颗粒（3-6纳米）组成。讨论了BFO纳米管可能的形成机制。
