【摘要】 报道对采用纳米粉料制作的γAl2O3基气敏元件的稳定性的研究结果。分别采用纳米粉料和微米级粉料制备了γAl2O3基气敏元件,该气敏元件对碳氢化合物还原性气体敏感;连续17个月测定了这些气敏元件对甲烷的气敏特性;通过XPS等技术分别在3个阶段对这两种元件的表面化学元素含量进行了表征。结果表明,元件失效的原因之一是由于在气敏反应过程中由于部分反应产物在表面沉积造成表面活性位减少,并导致吸附能力下降所致;而元件失效或不稳定与使用过程中元件表面有沉积物有关。通过以上研究工作,找出了利用纳米粉料制备气敏元件失效快和长期工作稳定性差的部分原因,为该类材料的进一步发展提供实验依据。更多还原

【Abstract】 The nano-crystalline ceramic gas sensors based on γ-Al₂O₃ are fabricated and studied in the authors’ group. The nano-ceramic gas sensors possess very high sensitivity particularly at low concentration of gases. And this kind of gas sensors needs shorter response time than traditional ceramic gas sensors. However, the sensitivities and initial resistance values of these sensors shift strongly depend on time. The reasons of the shift are studied experimentally in some detail. The stability of the nano-crystal γ-Al₂O₃ based ceramics gas sensors were investigated by the method of XPS. The surface composition of the sensors with different powder size and working-time were examined by XPS technique. The experimental results are very useful for developing the nano-crystalline ceramic gas sensors.更多还原