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化学学报
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化学学报 ›› 2008, Vol. 66 ›› Issue (12): 1405-1410. 上一篇    下一篇

研究论文

掺铝铁饼状α-Fe2O3微粒的制备及性能

曹付玲a 吴育飞a 刘 辉*,a,b 魏 雨*,a,b   

  1. (a河北师范大学化学与材料科学学院 石家庄 050016)
    (b河北省无机纳米材料重点实验室 石家庄 050016)
  • 投稿日期:2007-10-09 修回日期:2008-01-15 发布日期:2008-06-28
  • 通讯作者: 刘辉

Preparation and Property of Discoid Aluminum-doped α-Fe2O3 Particles

CAO, Fu-Ling a WU, Yu-Fei a LIU, Hui *,a,b WEI, Yu *,a,b   

  1. (a College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050016)
    (b Key Laboratory of Inorganic Nanomaterial of Hebei Province, Shijiazhuang 050016)
  • Received:2007-10-09 Revised:2008-01-15 Published:2008-06-28
  • Contact: LIU, Hui

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采用液相催化相转化法, 以Fe(III)与Al(III)的共沉淀为前驱物合成了铁饼状α-Fe2O3微粒, 探讨了各种因素如铝离子的掺杂浓度、反应温度以及催化剂Fe(II)离子用量等对合成铁饼状α-Fe2O3微粒的影响, 并对产物进行了X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、电子衍射(ED)、X射线光电子能谱(XPS)等表征, 研究了样品的热稳定性及磁性能. 结果表明: 初始pH值为9, nFe(II)/nFe(III)≤0.04, nAl/nFe(III)＝0.14、反应温度为100～140 ℃时, 可制备出铁饼状α-Fe2O3微粒. 尽管铝和铁均为三价且二者的氧化物均具有刚玉结构, 但因二者离子半径的差异而使α-Fe2O3晶胞参数因铝取代铁而减小, 其矫顽力和剩磁也因铝取代而发生变化. 电子衍射证明该方法合成的微粒为单晶粒子, 且具有较好的热稳定性.

关键词: 铝掺杂, 铁饼状α-Fe2O3, 单晶粒子, 催化相转化

Discoid hematite particles were prepared by a catalytic phase transformation method using co-precipitates of Fe(III) and Al(III) as a precursor. The effect of various factors such as the concentration of Al(III) ions, reaction temperature, the level of Fe(II) on the formation of these hematite particles was investigated. The product was characterized by XRD, SEM, TEM, ED, XPS. The magnetism and thermal stability of the product were also studied. The result shows that these discoid hematite particles can be prepared at initial pH 9, molar ratio nFe(II)/nFe(III)≤0.04 and nAl/nFe(III)＝0.14 in 100～140 ℃. The substitution of Fe(III) with Al(III) in the structure may cause a change in unit cell edges and magnetic performance due to their different ionic radii, although Fe and Al ions have the same valence and their oxides are isostructural equivalents belonging to the corundum system. The discoid α-Fe2O3 particles have been confirmed to be single crystal particles by ED pattern and they have good thermal stability.

Key words: Al-doping, discoid α-Fe2O3, single crystal particle, catalytic phase transformation