The influence of the synthesis method on the thermal conductivity of Eu₂Zr₂O₇ and Eu₂Hf₂O₇

The article presents research results on assessing the thermal properties of two materials dedicated to potential insulating layers of thermal barrier coatings. The scope of the research included determining the parameters of the powder synthesis and consolidation process using the PCM and SSR methods and the DTA and TG methods. The thermal parameters of the powder calcination and sintering process were determined on their basis. A detailed description of the impact of individual process stages was made, including a description of microstructural changes. The final element of this part of the research was preparing material in pellets dedicated to testing thermal diffusivity and thermal conductivity using the pulsed laser method. These studies have shown that europium zirconate, with relatively more significant chemical and phase composition heterogeneity from using the SSR process, has better insulating properties. This suggests that using this method allows the creation of a material with lower chemical homogeneity but better-insulating properties, which results from stronger phonon scattering in areas, e.g., with non-stoichiometric chemical composition. From the point of view of methodological correctness, it is more advisable to use the PCM method, which allows the extraction of materials with high homogeneity but worse insulating properties.