Fig. 4

Proton conductivities. Arrhenius plots of the proton conductivities of a I, b II, and c III at (298–368 K and RH 75%). Nyquist plot of the impedance spectrum at 308 K (as a representative) is shown under each Arrhenius plot

Proton conductivities. Arrhenius plots of the proton conductivities of a I, b II, and c III at (298–368 K and RH 75%). Nyquist plot of the impedance spectrum at 308 K (as a representative) is shown under each Arrhenius plot