Singh Virendra, Babu Suresh, Karakoti Ajay Singh, Agarwal Arvind, Seal Sudipta
Surface Engineering and Nanotechnology Facility, Advanced Materials Processing and Analysis Center (AMPAC), Mechanical Materials Aerospace Engineering, Engineering Building, Room #381, PO Box 162455, University of Central Florida, Orlando, FL 32816, USA.
J Nanosci Nanotechnol. 2010 Oct;10(10):6495-503. doi: 10.1166/jnn.2010.2523.
Doped ceria has been considered for high oxygen ion conductivity for solid oxide fuel cells. In the present study, 20 mole% samarium doped nano ceria powder was prepared by wet chemical synthesis and sintered at different temperatures to retain submicron grains (> 92-96% density). ionic conductivity of the sintered pellets was measured using impedance spectroscopy as a function of temperature (200-800 degrees C). The total maximum conductivity was 1.0 x 10(-2)S.cm(-1) (at 600 degrees C) for samples sintered at 1200 degrees C. The activation energy at higher test temperature decreases with the decrease in the sintering temperature (by 25%). The grain boundary, grain interior conductivity and activation energy of the electrolyte were correlated to the resulting microstructure. It has been demonstrated that use of doped nano ceria powder as precursor not only reduced the sintering temperature but also provided segregation free grain boundary for engineering higher conductivity dense electrolytes.
掺杂二氧化铈已被认为具有用于固体氧化物燃料电池的高氧离子传导性。在本研究中，通过湿化学合成法制备了20摩尔%钐掺杂的纳米二氧化铈粉末，并在不同温度下烧结以保留亚微米晶粒（密度>92 - 96%）。使用阻抗谱测量烧结颗粒的离子电导率作为温度（200 - 800℃）的函数。对于在1200℃烧结的样品，总最大电导率为1.0×10⁻²S·cm⁻¹（在600℃）。较高测试温度下的活化能随着烧结温度的降低而降低（降低25%）。电解质的晶界、晶粒内部电导率和活化能与所得微观结构相关。已经证明，使用掺杂纳米二氧化铈粉末作为前驱体不仅降低了烧结温度，而且为设计具有更高电导率的致密电解质提供了无偏析的晶界。
