La0.8Sr0.2Ga0.8Mg0.2O3与La0.8Sr0.2Ga0.8Mg0.15Co0.05O3电导的对比

采用固相合成法制备了La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282)和La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5), 利用四电极交流阻抗法和Hebb-Wagner 极化法对比研究了两种材料的总电导率和电子电导率. 实验结果表明, LSGM8282 的总电导率与氧分压无明显依赖关系, 而LSGMC5 的总电导率在高氧分压区随氧分压降低而增加,在中等氧分压区域基本保持不变. 在973-1173 K的温度范围内, LSGM8282的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和1/4.在1073-1173 K的温度范围内, LSGMC5的自由电子电导率以及电子空穴电导率的氧分压级数分别为-1/4和约为1/8, 表明LSGMC5的空穴产生机制可能与LSGM8282不同. LSGM8282 的氧离子电导率与氧分压无关, 而LSGMC5 的氧离子电导率在高氧分压区随氧分压的减小而增加.

Comparison between the Electrical Conductivities of La0.8Sr0.2Ga0.8Mg0.2O3 and La0.8Sr0.2Ga0.8Mg0.15Co0.05O3

La0.8Sr0.2Ga0.8Mg0.2O3(LSGM8282) and La0.8Sr0.2Ga0.8Mg0.15Co0.05O3 (LSGMC5) are two kinds of excellent electrolytes for intermediate temperature solid oxide fuel cells (ITSOFCs ). LSGM8282 and LSGMC5 were prepared using solid state reaction in this study. Total electrical conductivities and electronic conductivities of LSGM8282 and LSGMC5 were comparatively studied using four-probe AC impedance spectrometry and Hebb-Wagner polarization.The results showed that the total electrical conductivity of LSGM8282 had no dependency on oxygen partial pressures. However, the total electrical conductivity of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures. Within the temperature range of 973-1173 K, the orders of dependency of the electron conduction and hole conduction of LSGM8282 on the oxygen partial pressure was -1/4 and 1/4, respectively. Within the temperature range of 1073-1173 K, the orders of dependency of the electron conduction and hole conduction of LSGMC5 on the oxygen portial pressure was -1/4 and about 1/8, respectively. The oxygen ion conductivity of LSGM8282 had no dependency on oxygen partial pressures, while that of LSGMC5 increased with the decrease in oxygen partial pressures under high oxygen partial pressures.