室温下LaF_3单晶传感器的响应特性

Response Characteristics of LaF_3 Single Crystal Sensor at Room Temperature

采用LaF3单晶（掺杂0．2％EuF2和5％CaF2）作敏感材料，Pt片涂覆RuO2涂层作工作电极组装了电化学传感器，研究了该传感器在室温条件下，对不同含量的气体氧及水中溶解氧的响应特性，结果表明传感器的灵敏性较好，达到仪器化要求。根据实验结果，提出了LaF3单晶对02气体的响应机理。同时，利用LaF3单晶作为氟离子选择电极，测量了NaF溶液中的[F＋]浓度，测量结果显示了较好的准确性。此外，研究了LaF3单晶在Ar气条件下408～713K范围内的阻抗谱，发现其存在体阻抗和晶体缺陷及夹杂物所对应的两种阻抗特性。

A chemical sensor was made using LaF3 single crystal doped with 0.2% EuF2 and 5% CaF2 as the sensitive material and Pt tablet covered with RuO2 coating as the working electrode. The response characteristics of the sensor were studied to different-content gas oxygen and dissolved oxygen in water at room temperature. Results show that the response has a good sensibility. The response mechanism was proposed according to the result. The fluoride ion concentration of the NaF solution was measured with LaF3 single crystal as the fluoride ion selective electrode. The result is accurate. In addition, the electrochemical impedance spectroscopy of LaF3 single crystal was also measured at the temperature of 408-713 K under Ar atmosphere. It is found that there are impedance characteristics of body impedance, as well as inclusions and crystal defects impedance in LaF3 single crystal.