Application of CeO₂-SiO₂ glass to the oxygen sensor

Abstract

Nowadays, oxygen sensors attached to gasoline and diesel engines are required their downsizing, fast responsibility and high accuracy, in order to make exhaust gas clean and reduce the air pollution. The objective of this study is an application of porous oxide semiconductor which is prepared through phase separation of high temperature oxide melts to the oxygen sensors. CeO₂ was selected as a candidate of semiconductor, of which electronic conduction changes with oxygen partial pressure; furthermore CeO₂-SiO₂ binary system has stable immiscibility region at high temperature. Al₂O₃ was also added because it makes phase separation structure much finer and more homogeneous. The phase separation texture, crystallization behavior, and the electron conductivity of the melted samples have been investigated.