Structural and spectroscopic studies of rare earths doped ceria (RELa,Sc,Yb:CeO2) nanopowders
Structural and spectroscopic studies of rare earths doped ceria (RELa,Sc,Yb:CeO2) nanopowders
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DOI：
10.1016/j.ceramint.2014.01.076
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发表时间：
2014-07
影响因子：
5.2
通讯作者：
C. Jeyanthi;R. Siddheswaran;Pushpendra Kumar;V. Shankar;K. Rajarajan
中科院分区：
文献类型：
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作者：
C. Jeyanthi;R. Siddheswaran;Pushpendra Kumar;V. Shankar;K. Rajarajan
本文采用柠檬酸-硝酸盐自燃烧法合成了稀土离子掺杂的CeO 2（RELa，Sc，Yb：CeO 2）纳米颗粒，并对其进行了表征。Ce0.9La0.1O1.95将合成的粉末在700 °C下煅烧，并通过在1200 °C下烧结转化成圆柱形压块。X射线衍射研究证实，所有的组合物结晶为立方萤石结构的纯氧化铈。用扫描电子显微镜（SEM）和透射电子显微镜（TEM）观察了合成粉末和烧结体的微观结构。发现稀土（RE）掺杂的二氧化铈的颗粒尺寸在20至50 nm的范围内。通过红外光谱和拉曼光谱研究了功能分子、杂质和氧空位的光吸收。根据FTIR光谱，在1070和550 cm− 1处发现的吸收峰归因于金属-氧键的振动。在460 cm-1处观察到特征拉曼峰，在460-600 cm-1区域观察到氧空位的弱吸收。采用维氏压痕实验测量了烧结体的显微硬度值。RELa，Sc，Yb：CeO 2的硬度值在4700 ~ 7200 MPa之间。
In the present article, a simple and cost-effective citrate nitrate auto-combustion method was used for the high-yield synthesis of rare-earth (RE) ions doped ceria (RELa,Sc,Yb:CeO2) in the form of Ce0.9La0.1O1.95, Ce0.9Sc0.1O1.95and Ce0.9Yb0.1O1.95nanoparticles. The as-synthesized powders were calcined at 700 °C and converted into cylindrical compacts by sintering at 1200 °C. The X-ray diffraction study confirmed that all the combinations crystallized as the cubic fluorite structure of pure ceria. The microstructure of the synthesized powders and sintered bodies was examined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The particles size of the rare-earth (RE) doped ceria was found to be in the range from 20 to 50 nm. The optical absorption by functional molecules, impurities and oxygen vacancies was analyzed by FTIR and Raman spectroscopic studies. From the FTIR spectrum, the absorption peak found at 1070 and 550 cm−1was attributed to the vibrations of metal–oxygen bonds. The characteristic Raman peak was observed at 460 cm−1and weak absorptions of oxygen vacancies were observed in the region 460–600 cm−1. The micro-hardness values of the sintered compacts were measured using Vickers indentation experiments. The hardness values of the RELa,Sc,Yb:CeO2were in the range from 4700 to 7200 MPa.