Fig. 4: The effect of atmosphere on total conductivity of screened (from ML model) perovskites.

Type I (AO + BO2), shown in plots a–c, and type II (A2O3 + A2O3), shown in plots d–f, perovskites. The conductivities are shown at atmospheres of wet (3% H2O) H2 (a, d); wet air (b, e); and pure O2 (c, f). The white region refers to proton conductors, purple to oxide ion conductors, dark green to mixed protonic/electronic, light green to mixed oxide/electronic, orange to mixed protonic/oxide, and brown to purely electronic conductors. There is a transition from protonic to electronic conductivity indicated by increase in electronic (brown) and mixed protonic and mixed oxide (green) colors due to inclusion of holes in presence of O2.