Impact of point defects on the elastic properties of BaZrO3: Comprehensive insight from experiments and ab initio calculations

摘要: Abstract Acceptor doped BaZrO3 is the prototype of proton conducting perovskites which are strong interest as electrolytes for intermediate temperature fuel cells. Elastic properties both dry and hydrated Y-doped (1.5–17 mol% Y) were determined using ultrasound time flight (TOF) measurements, complemented by ab initio calculations allow an analysis different contributions. The experimental theoretical findings consistent reveal a decrease Young's, shear bulk moduli upon increasing dopant concentration. This attributed to combined effect (i) macroscopic lattice chemical expansion mainly caused differing ionic radii, (ii) presence point defects such acceptors Acc Zr ′ (with decreased cation charge), oxygen vacancies V O • , protonic OH (hydroxide ions on oxide ion sites) that locally weaken bonds in perovskite structure. from modified parameter minor relative weakening bonds. elastic differ only slightly between dehydrated samples. with acceptor vacancy concentrations much stronger (−5.8% Y:BaZrO3 per vacancies) compared similar earlier investigations Gd-doped CeO2 (−2% Gd:CeO2). result indicates greater ABO3 linear B fluorites strongly bent M-O-M