Non?Classical Electrostriction in Hydrated Acceptor Doped BaZrO ₃ : Proton Trapping and Dopant Size Effect

Point defects such as oxygen vacancies and protonic interstitials are not only essential for ionic conductivity in oxides since they also affect the mechanical electromechanical properties. These properties of nominally dry hydrated proton-conducting BaZr0.85M0.15O2.925+?H2? (M = Al, Ga, Sc, In, Y, Eu) ceramics investigated. Doping decreases Young's modulus with increasing radii difference between dopant host. Nominally samples show consistently higher moduli than samples. All exhibit large non-classical electrostriction, a negative electrostriction coefficient M33<0. M33 shows saturation field non-ideal Debye relaxation frequency. The low-frequency value both similar dependence on radius modulus. For samples, frequency increases by factor >100 series Ga-Y, emphasizing importance proton trapping, Y-doped having minimal trapping energy. This coincides fact that strain is smallest. In light these findings, it concluded present data give strong evidence existence defect-related elastic dipoles acceptor doped barium zirconate originates their reorientation under electric field.