A solid state reaction method was used to prepare the perovskite-structured compounds BaZrl-xYxO3-a （x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3）. The X-ray diffraction （XRD） pattern indicated that the target perovsldte ...A solid state reaction method was used to prepare the perovskite-structured compounds BaZrl-xYxO3-a （x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3）. The X-ray diffraction （XRD） pattern indicated that the target perovsldte phases were obtained. With increasing Y con- centration the unit cell parameters of BaZrl-xYxO3-a samples were expanded, and Y doping became more difficult. However, high synthesis temperature is helpful to promote Y doping. The SEM results showed that the samples exhibited poor sinterability with in- creasing Y-doping content. Thermal gravimetric （TG） curves analysis showed the more mass decreasing of BaZrl-xYxO3-a （0≤x≤0.3） samples at high temperature with more Y doping and more proton introducing. The electrochemical impedance spectra （EIS） of specimens showed that conductivities of BaZrl_xYxO3（0≤x≤0.3） increased with increasing temperature from 300 to 900 ℃ in wet air. At 900 ℃, the conductivity of BaZrl-xYxO3-a （0≤x≤0.3） first increased with increasing doped amount of Y, and reached the high- est value of 1.07x 104 S/cm when x was 0.2, then decreased gradually with further increasing Y content. At 600 ℃, BaZr0.75Y0.2503-a displayed the highest conductivity, while the conductivity of BaZro.rYo.303-a was the highest at 300 ℃. The results indicated that there should be an optimum Y doping concentration yielding the highest conductivity at a constant temperature, and the optimum Y doping concentration should increase in the humidity atmosphere as the temperature decreases. So increasing the Y-doping concen- tration is helpful to improve the conductivities of BaZrl-xYxO3-a materials at low temperature.展开更多
基金Project supported by National Natural Science Foundation of China （51074038, 51274057） and National High Technology Research and Development Program of China （2013AA030902）
文摘A solid state reaction method was used to prepare the perovskite-structured compounds BaZrl-xYxO3-a （x=0, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3）. The X-ray diffraction （XRD） pattern indicated that the target perovsldte phases were obtained. With increasing Y con- centration the unit cell parameters of BaZrl-xYxO3-a samples were expanded, and Y doping became more difficult. However, high synthesis temperature is helpful to promote Y doping. The SEM results showed that the samples exhibited poor sinterability with in- creasing Y-doping content. Thermal gravimetric （TG） curves analysis showed the more mass decreasing of BaZrl-xYxO3-a （0≤x≤0.3） samples at high temperature with more Y doping and more proton introducing. The electrochemical impedance spectra （EIS） of specimens showed that conductivities of BaZrl_xYxO3（0≤x≤0.3） increased with increasing temperature from 300 to 900 ℃ in wet air. At 900 ℃, the conductivity of BaZrl-xYxO3-a （0≤x≤0.3） first increased with increasing doped amount of Y, and reached the high- est value of 1.07x 104 S/cm when x was 0.2, then decreased gradually with further increasing Y content. At 600 ℃, BaZr0.75Y0.2503-a displayed the highest conductivity, while the conductivity of BaZro.rYo.303-a was the highest at 300 ℃. The results indicated that there should be an optimum Y doping concentration yielding the highest conductivity at a constant temperature, and the optimum Y doping concentration should increase in the humidity atmosphere as the temperature decreases. So increasing the Y-doping concen- tration is helpful to improve the conductivities of BaZrl-xYxO3-a materials at low temperature.
