Origin of colossal dielectric behavior in hydrothermally prepared non-stoichiometric α-MnO2 nanorods

The effects of Fe-doping on MnO2: phase transitions, defect structures and its influence on electrical properties

“…This is probably due to the number of ions diffusing more, causing the carrier mobility that is associated with transport to decrease. 52 Moreover, at x = 0.15, the phase transformation from α-MnO 2 to R-MnO 2 significantly affects the conductivity of the sample. A small tunnel (2 × 1) at R-MnO 2 inhibits the ion diffusion process.…”