Effect of lattice volume and strain on the conductivity of BaCeY-oxide ceramic proton conductors

TL;DR

This study investigates how lattice volume and strain influence proton conductivity in yttrium-doped barium cerate ceramics, revealing that increased pressure raises activation energy and suggesting lattice expansion as a future strategy.

Contribution

It provides experimental evidence linking lattice volume and strain to proton conductivity, highlighting the potential of lattice expansion to enhance ceramic proton conductors.

Findings

Activation energy increases with pressure from 0.62 eV to 0.73 eV.

Lattice volume change of 0.7% correlates with conductivity variations.

Expanding lattice may lower activation energy under tensile strain.

Abstract

In-situ electrochemical impedance spectroscopy was used to study the effect of lattice volume and strain on the proton conductivity of the yttrium-doped barium cerate proton conductor by applying the hydrostatic pressure up to 1.25 GPa. An increase from 0.62 eV to 0.73 eV in the activation energy of the bulk conductivity was found with increasing pressure during a unit cell volume change of 0.7%, confirming a previously suggested correlation between lattice volume and proton diffusivity in the crystal lattice. One strategy worth trying in the future development of the ceramic proton conductors could be to expand the lattice and potentially lower the activation energy under tensile strain.