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纳米α-Fe2O3以其优良的生物相容性、环境友好性、稳定性、催化性、以及磁性被广泛的应用于生物医学、颜料、催化、传感以及半导体等领域.为了实现不同形貌纳米α-Fe2O3的工业化可控合成,我们采用一步水热法,通过控制体系的反应时间,依次制备出了纺锤体状、管状和轮胎状的α-Fe2O3纳米结构,并利用X射线衍射仪、扫描电子显微镜和透射电子显微镜对产物进行了表征.体系中磷酸根离子在α-Fe2O3晶面上的特异性吸附是主导α-Fe2O3形貌演进的关键性因素.其作用主要体现在两个方面:一是使α-Fe2O3颗粒产生各向异性生长,形成纳米纺锤体;二是阻止某些晶面参与质子轰击反应,形成α-Fe2O3纳米管,进而促进体系中Fe4(PO4)3(OH)3相的形成与α-Fe2O3相的再结晶,最终形成轮胎状纳米结构.通过超导量子干涉仪对产物的磁性能表征,发现产物的不同形貌以及形状各项异性会对矫顽力、磁化强度以及低温磁性相变温度等磁学参量产生显著的影响.
Nanocrystalline α-Fe2O3 has been widely used in biomedicine, pigment, catalysis, sensing and semiconductors for its excellent biocompatibility, environmental friendliness, stability, catalytic activity and magnetism. α-Fe2O3 was synthesized in a controlled manner. One-step hydrothermal method was used to prepare α-Fe2O3 nanostructures in spindle, tube and tire shape by controlling the reaction time of the system. X-ray diffractometry (XRD) Electron microscopy and transmission electron microscopy were used to characterize the product.The specific adsorption of phosphate ions on the α-Fe2O3 crystal plane was the key factor that led to the morphological evolution of α-Fe2O3.The effects of this reaction were mainly reflected in two aspects: First, the α-Fe2O3 particles grow anisotropically to form nanospindles; second, some crystal faces are prevented from participating in the proton bombardment reaction to form α-Fe2O3 nanotubes, and then the Fe4 (PO4) 3 (OH) 3 Phase formation and α-Fe2O3 phase recrystallization, the final formation of tire-shaped nanostructures by superconducting quantum interferometer on the magnetic properties of the product and found that the different morphologies of the product and the shape of the opposite sex will coercion Force, magnetization and low temperature magnetic phase transition temperature and other magnetic parameters have a significant impact.