The X ray diffraction spectra and X ray photoelectron spectroscopy were measured for Sr doped La 1- x Sr x CoO 3 materials with perovskite structure prepared by the solid state reaction method. The in...The X ray diffraction spectra and X ray photoelectron spectroscopy were measured for Sr doped La 1- x Sr x CoO 3 materials with perovskite structure prepared by the solid state reaction method. The influence of heat treatment temperature on the average crystal size of La 1- x Sr x CoO 3 was studied. The surface chemical states of La 1- x Sr x CoO 3 cathodes with different Sr doped content were discussed. The experimental results show that average crystal size of La 1- x Sr x CoO 3 under the condition of heat treatment in the range of 900～1200 ℃ is larger than that at other temperatures, which is of benefit to forming porous electrodes. When La is replaced by Sr gradually, the oxygen vacancy concentration increases. It is of benefit to enhancing the transport property of oxygen ion.展开更多
The superfine powders of Ln0.5 Sr0.5 CoO3 （Ln = La, Pr, Nd, Sm, Eu） were obtained by solid state reactions. The crystal structure and electrical transport properties of samples doped with different rare earth elemen...The superfine powders of Ln0.5 Sr0.5 CoO3 （Ln = La, Pr, Nd, Sm, Eu） were obtained by solid state reactions. The crystal structure and electrical transport properties of samples doped with different rare earth elements as well as the forming process of the Perovskite structure were studied. The result shows that when the temperature reaches 1200 ℃, the samples will become a steady and unitary Perovskite phase by solid state reactions. The conductive behavor at low temperature is consistent with small polaron mechanism （i. e., localized electronic carriers having a thermally activated mobility）. However, the maximum of conductivity appears at about 700 ℃, and the conductivity of La0.5Sr0.5CoO3 is the biggest in the intermediate-temperature （600 - 850 ℃ ）, so it is fit for cathode material of intermediate-temperature solid oxide fuel cells.展开更多
文摘The X ray diffraction spectra and X ray photoelectron spectroscopy were measured for Sr doped La 1- x Sr x CoO 3 materials with perovskite structure prepared by the solid state reaction method. The influence of heat treatment temperature on the average crystal size of La 1- x Sr x CoO 3 was studied. The surface chemical states of La 1- x Sr x CoO 3 cathodes with different Sr doped content were discussed. The experimental results show that average crystal size of La 1- x Sr x CoO 3 under the condition of heat treatment in the range of 900～1200 ℃ is larger than that at other temperatures, which is of benefit to forming porous electrodes. When La is replaced by Sr gradually, the oxygen vacancy concentration increases. It is of benefit to enhancing the transport property of oxygen ion.
文摘The superfine powders of Ln0.5 Sr0.5 CoO3 （Ln = La, Pr, Nd, Sm, Eu） were obtained by solid state reactions. The crystal structure and electrical transport properties of samples doped with different rare earth elements as well as the forming process of the Perovskite structure were studied. The result shows that when the temperature reaches 1200 ℃, the samples will become a steady and unitary Perovskite phase by solid state reactions. The conductive behavor at low temperature is consistent with small polaron mechanism （i. e., localized electronic carriers having a thermally activated mobility）. However, the maximum of conductivity appears at about 700 ℃, and the conductivity of La0.5Sr0.5CoO3 is the biggest in the intermediate-temperature （600 - 850 ℃ ）, so it is fit for cathode material of intermediate-temperature solid oxide fuel cells.
