Synthesis and characterization of tungsten and barium co-doped La2Mo2O9 by sol-gel process for solid oxide fuel cells
来源期刊：Journal of Rare Earths2019年第9期
论文作者：Chang’an Tian Lingbo Shao Dongdong Ji Jie Yang Jinsong Xie Qiyi Yin Huirong Le
文章页码：984 - 988
摘 要：Herein, we demonstrate the synthesis of W and Ba co-doped La2Mo2O9（LBMWO） nanocrystalline powder by a sol-gel process. In all the compositions have general formulae La1.9Ba0.1Mo2-xWxO8.95（x = 0-0.40）. The crystal structure, microstructure and conductivity of LBMWO were characterized by X-ray diffraction, scanning electron microscopy and electrical impedance spectroscopy. In addition, the thermal and decomposition properties of the LBMWO gel were analyzed by differential scanning calorimetry-thermogravimetric. The results reveal that all LBMWO powders calcined at 700 ℃ have a cubic structure;the average crystallite size is about 48 nm. The unit cell parameter of LBMWO powders increases with increase in W content. The as-synthesized nanocrystalline LBMWO samples exhibit excellent sinterability and a relatively lower sintering temperature of 900 ℃. A high relative density of -96% is achieved after sintering at 900 ℃ which is in good agreeme nt with the re sults of the SEM. Moreover, W and Ba codoping suppresses the phase transition and effectively stabilizes the β-phase at low temperature. At the same time,La1.9Ba0.1Mo1.85W0.15O8.95 exhibits high ionic conductivity, 3.07 x 10-2 S/cm at 800 ℃. It is therefore concluded that co-doping can improve the properties of La2MO2O9 electrolytes.
Chang’an Tian，Lingbo Shao，Dongdong Ji，Jie Yang，Jinsong Xie，Qiyi Yin，Huirong Le
Department of Chemistry and Materials Engineering,Hefei UniversityDepartment of Engineering College of Engineering and Technology,University of Derby
摘 要：Herein, we demonstrate the synthesis of W and Ba co-doped La2Mo2O9（LBMWO） nanocrystalline powder by a sol-gel process. In all the compositions have general formulae La1.9Ba0.1Mo2-xWxO8.95（x = 0-0.40）. The crystal structure, microstructure and conductivity of LBMWO were characterized by X-ray diffraction, scanning electron microscopy and electrical impedance spectroscopy. In addition, the thermal and decomposition properties of the LBMWO gel were analyzed by differential scanning calorimetry-thermogravimetric. The results reveal that all LBMWO powders calcined at 700 ℃ have a cubic structure;the average crystallite size is about 48 nm. The unit cell parameter of LBMWO powders increases with increase in W content. The as-synthesized nanocrystalline LBMWO samples exhibit excellent sinterability and a relatively lower sintering temperature of 900 ℃. A high relative density of -96% is achieved after sintering at 900 ℃ which is in good agreeme nt with the re sults of the SEM. Moreover, W and Ba codoping suppresses the phase transition and effectively stabilizes the β-phase at low temperature. At the same time,La1.9Ba0.1Mo1.85W0.15O8.95 exhibits high ionic conductivity, 3.07 x 10-2 S/cm at 800 ℃. It is therefore concluded that co-doping can improve the properties of La2MO2O9 electrolytes.
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