Novel mid-temperature Y3+ → In3+ doped proton conductors based on the layered perovskite BaLaInO4

The possibility of isovalent substitution in the In-sublattice of layered perovskite BaLaInO4 was experimentally investigated. The yttrium doping leads to the increase of total and protonic conductivity up to 2 orders of magnitude. The solid solution BaLaIn1-xYxO4 (0 <= x <= 0.5) is mixed ionic-electronic (hole) conductor at the dry air. The increase in the water vapor partial pressure leads to the appearance of protons in the structure below 600 degrees C, which is confirmed by the decrease of activation energy from similar to 0.75 eV to similar to 0.52 eV for doped samples. Both undoped and doped BaLaIn1-xYxO4 samples are nearly pure (similar to 95%) proton conductors under wet air conditions below 400 degrees C. The most conductive Y-doped compositions BaLaIn0.8Y0.2O4 demonstrates the proton conductivity value 4.10(-5) S/cm at the 400 degrees C.

Automated summary

The possibility of isovalent substitution in the In-sublattice of layered perovskite BaLaInO4 was experimentally investigated. Yttrium doping significantly increased the total and protonic conductivity, and doped samples showed higher conductivity under wet air conditions.