Y_(1-x)Gd_xBaCo_4O_(7+δ)的微结构和氧吸附性能(英文)  

Microstructure and Oxygen Absorption Properties of Y_(1-x)Gd_xBaCo_4O_(7+δ)

作　　者：张亚梅[1] 吴小山[2] 韩汝取[1] 

机构地区：[1]江苏科技大学物理系,江苏镇江212003 [2]南京大学,固体微结构国家重点实验室,南京210093

出　　处：《硅酸盐学报》2012年第2期289-293,共5页Journal of The Chinese Ceramic Society

基　　金：江苏科技大学博士科研启动基金;校管基金(2009SL153J)资助项目

摘　　要：采用固相反应法制备了Y1-xGdxBaCo4O7+δ(x≤0.4)吸氧材料。利用X射线衍射(X-ray diffraction,XRD)和热重分析表征了样品的微结构和氧吸附性能。XRD结果表明:Gd掺杂量x≤0.2时,Y1-xGdxBaCo4O7+δ具有单相六方结构;x>0.2时,Y1-xGdxBaCo4O7+δ出现杂相。Rietveld精修XRD结果表明:Y1-xGdxBaCo4O7+δ(x≤0.2)样品的单胞参数和体积随Gd掺杂量增加而增大;Co—O键角变化不明显,Co—O键长变化较大,这使两种类型的CoO4四面体发生畸变。热重分析结果显示:从室温到1 000℃,所有样品经历两次氧吸附过程,Gd掺杂的YBaCo4O7+δ最大吸氧量低于母相YBaCo4O7+δ的吸氧量,与氧的激活能有关。Y1-xGdxBaC0407＋δ （x≤0.4） adsorbent materials were fabricated by solid state reaction. The microstructure and oxygen absorption were analyzed by X-ray diffraction （XRD） and thermogravimetry （TG）. When the Gd doping content x~ 0.2, Yl_xGdxBaC04OT＋~ was single phase with the hexagonal crystal structure. When x 〉 0.2, Y1 xGdxBaC04OT＋δ had some impurities. The Rietveld refinement XRD results showed that the unit cell parameters and volume of Y1-xGdxBaCo4OT＋δ （x≤0.2） increased with in- creasing the Gd doping content. The refinement results indicated that Co-O bond angles had little change and Co-O bond distances changed, resulting in the distortion of two types of CoO4 tetrahedra. TG analysis showed that all the samples underwent two oxygen absorption processes from room temperature to 1 000 ℃. The maximum mass increase of Y1-xGdxBaC04O7＋δ （x≤0.2） was less than that of YBaCo4OT＋δ related to the oxygen activation energy.

关 键 词：微结构 氧吸附 掺杂 畸变 RIETVELD精修 

分 类 号：O469[理学—凝聚态物理]