The electrical properties of Pt/Ga2O3/SiC metal oxide semiconductor devices are presented in this paper in order to determine the hydrogen sensing mechanism. This was achieved by studying the role of the interface states upon the introduction of hydrogen/hydrocarbon gas. Current–voltage (I–V), conductance–voltage (C–V) and capacitance–voltage (G–V) experiments have been carried out to investigate the gas sensing mechanism. The devices' hydrogen and propene gas sensitivities were also investigated. This was achieved by operating them as Schottky diodes and by measuring the change in output voltage when kept at a constant forward bias current. Voltage shifts over 1 V were observed. A discussion is also presented on the effect of operating temperature and ambient gas on the sensors' hydrogen response mechanism, which is attributed largely to the passivation and creation of energy states at the Ga2O3/SiC interface.

Ferroelectric and piezoelectric properties of the La‐doped intergrowth Aurivillius phase ceramics Bi5−xLaxTiNbWO15 and Bi7−xLaxTi4NbO21 (x = 0.00–1.75) were studied. It was found that the La doping is in favour of the domain switching. Owing to the impact of defects, the P–E hysteresis loops of the La‐doped Bi5TiNbWO15 ceramics are un‐symmetrical and the piezoelectric coefficients are quite low. Enhanced ferro‐/piezoelectric properties, such as 2Pr of 24.4 µC/cm2 (x = 0.50) and d33 of 16.6 pC/N (x = 0.75), were obtained in the Bi7−xLaxTi4NbO21 ceramics. The high temperature electrical behaviour indicates that the Bi5−xLaxTiNbWO15 ceramics are semiconducting whereas the La‐doped Bi7Ti4NbO21 ceramics are worthy to be further studied toward high temperature piezoelectric applications. Finally, the underlying materials design is discussed.