Defect properties of langasite and effects on BAW gas sensor performance at high temperatures

The electrical and defect properties of langasite (La3Ga5SiO14) were studied as a function of temperature, oxygen partial pressure and dopants in order to characterize its electrical behavior in relation to its performance as a bulk acoustic wave (BAW) gas sensor operating at elevated temperatures. Undoped, 5%–Nb donor doped, and 1%–Sr acceptor doped langasite specimens were studied. A defect model, shown to be consistent with experimental observations, was used to extract key defect parameters for the system. Implications for device operation are discussed.