High-Temperature Proton Conduction in LaSbO4

Lanthanum orthoantimonate was synthesized using a solid-state synthesis method. To enhance the possible protonic conductivity, samples with the addition of 1 mol % Ca in La-site were also prepared. The structure was studied by the means of X-ray diffraction, which showed that both specimens were single phase. The materials crystallized in the space group P2(1)/n. Dilatometry revealed that the material expanded non-linearly with the temperature. The nature of this deviation is unknown; however, the calculated linear fraction thermal expansion coefficient was 9.56x10(-6) K-1. Electrical properties studies showed that the material is a proton conductor in oxidizing conditions, which was confirmed both by temperature studies in wet in dry air, but also by the H/D isotope exchange experiment. The conductivity was rather modest, peaking at the order of 10(-6) S cm(-1) at 800 degrees C, but this could be further improved by microstructure and doping optimization. This is the first time protonic conductivity in lanthanum orthoantimonates is reported.

Automated summary

Lanthanum orthoantimonate was synthesized using a solid-state synthesis method, with the addition of 1 mol % Ca to enhance protonic conductivity. The materials were found to be single-phase and exhibited non-linear expansion with temperature. Studies showed the material to be a proton conductor under oxidizing conditions, with a conductivity of around 10(-6) S cm(-1) at 800 degrees C, which could be improved through microstructure and doping optimization.