Tetragonal zirconia based solid solutions are important materials for thermal barrier coatings (TBCs). The introduction of the third component to binary zirconia systems is regarded as a promising way to design novel high performance TBCs. The work reports the investigation of solid solution formation in ternary TiO₂–CeO₂–ZrO₂ system in the range 600–1100 °C obtained by using co-precipitation from mixed aqueous solution and freeze-drying. Phase evolution and stability of solid solutions were investigated using DSC, qualitative and quantitative XRD analysis with Rietveld refinement technique. The factors affecting the kinetics of phase formation i.e. powders dispersity, agglomerate strength, crystallite size, Ce³⁺/Ce⁴⁺ ratio were studied using PSD, XRD and ESCA techniques. The heat capacity dependence on temperature was measured experimentally for the first time for 5TiO₂–9CeO₂–86ZrO₂ composition via calorimetry technique using DSC. The obtained data significantly contributes to the schematic phase diagram suggested in the literature and allows to choose the optimal synthesis and processing conditions of ternary system compositions for their use for novel TBCs fabrication.