Proton Conductivity in Acceptor-Doped Simple Perovskites, ABO

5 Proton Conductivity in Acceptor-Doped Simple Perovskites, ABOs 

Proton conductivity is found in a range of perovskites, ABO3, covering all combinations of valence of the A and B cations. The protonic defects have to be compensated by some effectively negative defect, most often acceptor 

03 atm, calculated on basis of proton mobility and hydration thermodynamics parameters. Acceptor level is chosen as 10 mol% (3.33% of oxide ions are protonated at full hydration) for BaZrOa [20], BaCeOs [12], BaTbOa [21], BaThOa [21], SrCeOa [22], SrTiOa [20, 23], SrZrOa [20], CaZrOa [24, 25], LaScOa [26], and LaErOa [27]. Data for BCN17 

Among III-III perovskites, is the only common A-site cation. LaSc03 hydrates well but exhibits medium proton mobility and a proton conductivity peaking just above 10 S/cm. LaY03 and LaEr03 are also perovskite related, but with lower tolerance factors and lower conductivity. 

Sr- and Mg-substituted LaGaOs (LSGM) is another member where no protons are found [31]. Lattice modeling of this material has indeed predicted the hydration enthalpy to be positive (endothermic) [32]. 

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