竹节状α-Fe_2O_3纳米棒的制备、表征和性能研究

Preparation,Characterization and Property of Bamboo-Like α-Fe_2O_3 Nanobars

以硝酸铁为铁源,氨水为沉淀剂,聚乙二醇(PEG)为分散剂,采用共沉淀法制备氢氧化铁前驱体,然后将获得的前驱体在450℃、氮气保护下热处理2h,最后利用透射电镜、X射线衍射、拉曼光谱和近边X射线精细结构光谱(NEXAFs)表征样品的形貌和结构,并使用HH-50型振动样品磁强计测量样品在室温下的磁学行为。透射电镜结果显示,获得的样品由氧化铁纳米颗粒和竹节状氧化铁纳米棒组成,纳米颗粒的粒径范围为50～100nm,纳米棒的直径大约为10nm。XRD表征显示样品中氧化铁纳米棒和纳米颗粒为赤铁矿型α-Fe2O3;光谱实验结果证实了样品中氧化铁纳米颗粒和纳米棒的结构是α-Fe2O3;磁学性能测试表明获得的样品表现为典型铁磁性材料的磁滞回线,其饱和磁感应强度约为64.65emu.g-1,矫顽力的大小约为15.13Oe。

Firstly, hydroxide iron precursor was prepared by the co-precipitation method through using nitric iron as the source of iron, ammonia as precipitants, and poly-glycol as dispersant. Secondly, the precursor was calcined at 450 ℃ for 2 h under the protection of nitrogen. Finally, the images and structures of resultant powders were investigated by transmission electron microscopes （TEM）, X-ray diffraction （XRD）, Raman spectrum and the near-edge X-ray absorption fine structure （NEXAFS）, respectively, and the magnetic property of resultant powders was measured by a vibrating sample magnetometer （VSM HH-50）. The experimental results of TEM show that the products are composed of Fe2O3 nano-particles with sizes in the range of 50-100 nm and bamboo-like Fe2O3 nanobars about 10 nm in diameter. The experimental results of XRD and spectrum illuminate that the structures of products are a-Fe2O3. Moreover, magnetic properties measurement reveals that the products exhibit typical magnetic hysteresis loops of ferromagnetism materials, and their saturation magnetization and coercive force are approximately 64. 65 emu · g^-1 and 15.13 Oe, respectively.