类钙钛矿Pr_(1.3)Sr_(0.7)Ni_(0.7-x)Cu_(0.3)Fe_xO_(4+δ)材料的制备与传导性能研究

Preparation and Conductivity of Perovskite-like Structure Pr_(1.3)Sr_(0.7)Ni_(0.7-x)Cu_(0.3)Fe_xO_(4+δ) Materials

以硝酸盐和氧化物为原料,通过甘氨酸-硝酸盐法(GNP)合成出Pr_(1.3)Sr_(0.7)Ni_(0.7-x)Cu_(0.3)Fe_xO_(4+δ)(x=0,0.025,0.05,0.1)(PSNCF)粉体,经压制成形、烧结后得到烧结体样品。采用X射线衍射仪对煅烧后粉体的物相进行分析,利用扫描电子显微镜和能谱仪对样品的微观组织和元素分布进行了表征,采用四端子法和阻塞电极法测量了不同Fe掺杂量烧结体样品的电导率,并对材料的透氧性能进行了测试。实验结果表明,前驱体粉末在1000℃煅烧5 h后得到具有四方相的PSNCF粉体。烧结体试样在300~950℃间的总电导率均在200 S·cm^(-1)以上,且随Fe掺杂含量的增加有所下降;其中,Pr_(1.3)Sr_(0.7)Ni_(0.65)Cu_(0.3)Fe_(0.05)O_(4+δ)样品的氧离子电导率在950℃时最大达到0.194 S·cm^(-1)。另外,随Fe掺杂量增加,PSNCF材料的透氧率增大,950℃下,Fe掺杂量为0.05时(厚1 mm,40%O2-60%N_2),透氧率达0.034 mL·cm^(-2)·min^(-1),为未掺杂样品的3倍。

Pr1.3Sr0.7Ni0.7-xCu0.3FexO4＋δ（x = 0,0. 025,0. 05,0. 1）（PSNCF） powders were synthesized by the glycine nitrate method（GNP） using nitrates and oxides as raw materials. PSNCF samples were obtained by pressing and sintering the powders. Phase structure of the synthesized powders was characterized by X-ray diffraction analysis. Microstructure and elements distribution of the sintered specimens were investigated by scanning electron microscopy and energy dispersive spectroscopy.Electrical conductivity of sintered samples was measured by four probe method and electrode-blocking method. Oxygen permeability of the sintered samples was tested on oxygen permeation test device. The results show that PSNFC powders with tetragonal structure can be obtained by calcining the precursors at1000 ℃ for 5 h. Total electrical conductivity of the sintered PSNFC samples reaches above 200 S·cm-1 in 300-950 ℃,and decreases gradually with the increase of Fe doping amount. At 950 ℃,oxygen ionic conductivity of the Pr1.3Sr0.7Ni0.65Cu0.3Fe0.05O4＋δ samples is 0. 194 S·cm-1. The oxygen permeabilityincreases with the increase of Fe doping amount. At 950 ℃ under（40% O2-60% N2）/He mixed gases,oxygen permeability of the Pr1.3Sr0.7Ni0.65Cu0.3Fe0.05O4＋δ samples reaches 0. 034 mL · cm-2·min-1,which is 3 times as high as that of the undoped samples.