Formation mechanism and magnetic properties of three different hematite nanostructures synthesized by one-step hydrothermal procedure  

作　　者：LIU ChunTing MA Ji LIU YuLiang 

机构地区：[1]College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266061, China [2]School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471003, China

出　　处：《Science China Chemistry》2011年第10期1607-1614,共8页中国科学（化学英文版）

基　　金：supported by the National Natural Science Foundation of China (51072086)

摘　　要：The spindle-like, tubular, and tire-like hematite were successively fabricated by a facile, one-step hydrothermal procedure, which is of great importance in facilitating the controllable-synthesis process of commercial industrialization. A mechanism involving a formation-dissolution process was proposed based on the X-ray diffraction, scanning electron microscopy, trans-mission electron microscopy, and high-resolution transmission electron microscopy analysis. It was demonstrated that the presence of phosphate ions during the reaction process is crucial to the morphology evolution of hematite. Their different ad-sorption ability on the different crystallographic planes of hematite and a coordination effect with ferric ions could promote the preferential dissolution of the spindle-like hematite precursors along the long axis [001] from the tips down to the interior, and thus yield the tubular and tire-like hematite one by one with the increasing reaction time. The magnetic measurements have also been performed to investigate the different magnetic properties such as coercivity and low-temperature transition behavior of three different hematite nanostructures.The spindle-like, tubular, and tire-like hematite were successively fabricated by a facile, one-step hydrothermal procedure, which is of great importance in facilitating the controllable-synthesis process of commercial industrialization. A mechanism involving a formation–dissolution process was proposed based on the X-ray diffraction, scanning electron microscopy, trans-mission electron microscopy, and high-resolution transmission electron microscopy analysis. It was demonstrated that the presence of phosphate ions during the reaction process is crucial to the morphology evolution of hematite. Their different ad-sorption ability on the different crystallographic planes of hematite and a coordination effect with ferric ions could promote the preferential dissolution of the spindle-like hematite precursors along the long axis [001] from the tips down to the interior, and thus yield the tubular and tire-like hematite one by one with the increasing reaction time. The magnetic measurements have also been performed to investigate the different magnetic properties such as coercivity and low-temperature transition behavior of three different hematite nanostructures.

关 键 词：hematite （-Fe2O3） hydrothermal synthesis nanospindle NANOTUBE nanotire 

分 类 号：TQ174.758[化学工程—陶瓷工业] P618.505[化学工程—硅酸盐工业]