Influence of Fuel Composition in Solution Combustion Synthesis on the Structure and Thermoelectric Properties of La-Doped SrTiO3

Le résumé fourni par la source

Abstract High-temperature thermoelectric SrTiO3 powders, including La-doped (Sr0.95La0.05)TiO3, were synthesized using solution combustion synthesis. It was found that using urea as the organic fuel leads to the formation of a polyphase material consisting of 80 wt % SrTiO3 and 20 wt % TiO2 along with Sr2TiO4. The introduction of a fuel mixture of urea and glycine into the reaction solution significantly improved homogeneity of the powder, increasing the proportion of the target phase to 95 wt %. Spark plasma sintering further homogenized the powder, reducing amount of the impurity phase TiO2 to less than 5 wt %. The study demonstrated that doping, phase composition, and porosity have a significant impact on the thermoelectric properties of SrTiO3. The presence of TiO2 secondary phase and porosity was shown to regulate the material’s electrical and thermal conductivities. La doping affected the charge carrier concentration, and together with the other factors, enabled the production of a dense (Sr0.95La0.05)TiO3 sample with a figure of merit ZT ≈ 0.23 at 950 K. The findings underscore the significance of controlling phase composition, doping, and defect structure to enhance the thermoelectric performance of SrTiO3, paving the way for the design of energy-efficient materials applicable in thermal energy conversion technologies.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.