Influence of Microwave-Assisted Pechini Method on La0.80Sr0.20Ga0.83Mg0.17O3-delta Ionic Conductivity.

With the aim of investigating the microwave influence on the electrolyte material properties, La0.80Sr0.20Ga0.83Mg0.17O2.815 was prepared by both a conventional and a microwaveassisted sol-gel Pechini method. With respect to the conventional Pechini method (hereafter SGP), the microwave assisted process (hereafter MWA-SGP) guaranteed a faster procedure, reducing the time needed to remove the excess solvents to complete the polyesterification reaction from some days to a few hours. In fact, when a MWA-SGP method was used, powders having higher phase purity were obtained. The sintering process at 1,450 °C of the powders prepared by both methods yielded pellets with similar density values (>=92% of theoretical). Nevertheless, only by microwave-assisted process single-phase products were obtained and no secondary phases such as tetragonal LaSr-GaO4 and LaSrGa3O7 were detected. These by-products have been demonstrated to be detrimental for conductivity. Indeed, pellets obtained by MWA-SGP method showed oxygen ionic conductivity values higher (about 30-40%) than those checked for SGP samples, thus demonstrating the important role of the microwave process on reducing time and costs and on improving the electrolyte properties.