The application of solid fluoride electrolytes in chemical sensors

The potential of chemical sensors for improving the quality control and efficiency of industrial processes has resulted in considerable research activity in the development of chemical sensors. Due to the combination of good ionic conductivity with low electronic conductivity, a number of solid metal fluorides are excellent electrolytes and thus have been used in chemical sensors for numerous applications ranging from room temperature oxygen gas sensors to sensors for use in the processing of molten metals. The most studied metal fluorides are those which form the cubic fluorite crystal structure, such as CaF2 and PbF2. However, recent research activity has shown that fluorides which form other crystal structures, such as tysonite (e.g. LaF3) and rutile (e.g. MgF2), have promising applications in chemical sensors. In this paper, the application of solid fluoride electrolytes in chemical sensors will be reviewed. (C) 1997 Elsevier Science S.A.