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对中温固体氧离子导体———La0.9Sr0.1Ga0.8Mg0.2O2.85材料分别在1300,1350,1400和1450℃4个温度下烧结4 h,之后对其进行XRD,SEM和阻抗谱等测试。实验结果显示:当烧结温度为1400℃时,样品为单一的La0.9Sr0.1Ga0.8Mg0.2O2.85晶体相,晶粒排列较为紧密,致密度达到96.6%,且不同温度下的电导率均最高。然后,选取在该温度下烧结的大小不同的两片陶瓷片制作了一种新型结构的电流型氧传感器。改变测试环境中的氧浓度的大小,在600,650和700℃3个温度下对传感器的气敏特性进行了测试。从测试的结果中发现:传感器极限电流与氧浓度并不呈现传统的线性关系。根据Fick第一定律、法拉第定律和Langmuir吸附方程对这种氧传感器的极限电流与氧浓度的关系进行了理论推导,得到了新的关系表达式,实验结果也验证了理论推导出的结果的合理性。此外,在温度为600℃时,对该传感器的响应时间进行了测试,上升和下降响应时间均为10～15 s。
The medium-temperature solid oxygen ion conductor, La0.9Sr0.1Ga0.8Mg0.2O2.85, was sintered at 4 temperatures of 1300, 1350, 1400 and 1450 ℃ for 4 h, respectively, and then subjected to XRD, SEM and impedance spectroscopy test. The experimental results show that when the sintering temperature is 1400 ℃, the sample is a single La0.9Sr0.1Ga0.8Mg0.2O2.85 crystal phase, the grains are arranged closely, the density reaches 96.6%, and the conductivity at different temperatures are highest. Then, two different sizes of ceramic sintered at this temperature were chosen to fabricate a new type of current-type oxygen sensor. The oxygen concentration in the test environment was changed. The gas sensing properties of the sensor were tested at three temperatures of 600, 650 and 700 ℃. From the test results, it is found that the current limit of the sensor does not show a traditional linear relationship with the oxygen concentration. According to Fick’s first law, Faraday’s law and Langmuir’s adsorption equation, the relationship between the limiting current of oxygen sensor and the oxygen concentration was theoretically derived and a new relational expression was obtained. The experimental results also verify that the theoretical derivation result is reasonable Sex. In addition, the response time of the sensor was tested at a temperature of 600 ° C, and both the rise and fall response times were 10 to 15 seconds.