The paper presents a reliable technology combining sol–gel synthesis and spark plasma sintering (SPS) to obtain SrTiO₃ perovskite-type ceramics with excellent physicomechanical properties and hydrolytic stability for the long-term retention of radioactive strontium radionuclides. The Pechini sol–gel method was used to synthesize SrTiO₃ powder from Sr(NO₃)₂ and TiCl₃ (15%) precursors. Ceramic matrix samples were fabricated by SPS in the temperature range of 900–1200 °C. The perovskite structure of the synthesized initial SrTiO₃ powder was confirmed by X-ray diffraction and thermal analysis results. Scanning electron microscopy revealed agglomeration of the nanoparticles and a pronounced tendency for densification in the sintered compact with increasing sintering temperature. Chemical homogeneity of ceramics was confirmed by energy dispersive X-ray analysis. Physicochemical characteristic studies included density measurement results (3.11–4.80 g·cm⁻³), dilatometric dependencies, Vickers microhardness (20–900 HV), and hydrolytic stability (10⁻⁶–10⁻⁷ g·cm⁻²·day⁻²), exceeding GOST R 50926-96 and ISO 6961:1982 requirements for solid-state matrices. Ceramic sintered at 1200 °C demonstrated the lowest strontium leaching rate of 10⁻⁷ g/cm²·day, optimal for radioactive waste (RAW) isolation. The proposed approach can be used to fabricate mineral-like forms suitable for RAW handling.

We study the synthesis of Ti₂AlC MAX-phase ceramics via spark plasma sintering (SPS), focusing on the effects of temperature, precursor composition, and transition metal doping (Mo, Ta, Hf, W, Y, and Mn). Optimized sintering parameters were established, defining the precursor ratios necessary for the formation of Ti₂AlC with >90% yield. Structural and compositional analyses revealed that select transition metals—Ta, Hf, W, and Y—could be incorporated into the Ti₂AlC lattice, which resulted in >90% yield for each transition metal-doped MAX phase. In contrast, Mo and Mn predominantly formed separate phases. These findings provide insights into the controlled synthesis of MAX-phase materials with tunable properties for high-performance applications.

We study the synthesis of Ti₂AlC MAX-phase ceramics via spark plasma sintering (SPS), focusing on the effects of temperature, precursor composition, and transition metal doping (Mo, Ta, Hf, W, Y, Mn). Optimized sintering parameters were established, defining the precursor ratios necessary for Ti₂AlC formation. Structural and compositional analyses revealed that select transition metals—Ta, Hf, W, and Y—can be incorporated into the Ti₂AlC lattice, whereas Mo and Mn predominantly form separate phases. These findings provide insights into the controlled synthesis of MAX-phase materials with tunable properties for high-performance applications.

The paper presents new experimental data on the influence of post-annealing temperature conditions on the microstructure and optical properties of Ce:GGAG (Gd3Al2Ga3O12 doped with Ce3+) ceramics obtained by spark plasma sintering (SPS). Post‐annealing was carried out in an oxygen‐containing atmosphere in the temperature range of 1200–1350 °C for 5 h. Microstructural analysis revealed thermally activated grain growth from 3.5 to 11.5 μm with increasing temperature. At 1300 °C, the onset of secondary recrystallization was observed, as evidenced by the deviation of the grain size distribution from the log‐normal law, which leads to the formation of a coarse‐grained and less homogeneous structure at 1350 °C. Spectroscopic studies demonstrated that annealing at 1200 °C provides high luminescence characteristics, including maximum emission intensity and an average decay time of 52.4 ns. In contrast, increasing the annealing temperature (1250–1350 °C) results in deteriorated optical properties, manifested as a decrease in luminescence intensity and a reduction of the decay time to 44.4 ns. It has been proven that these effects are associated with enhanced light scattering at coarsened pores and an increased contribution of non‐radiative recombination at grain boundaries. The obtained results establish a clear relationship between structure and properties, demonstrating that post‐annealing at 1200 °C for 5 h is the optimal regime for Ce:GGAG ceramics synthesized by SPS, ensuring high optical transparency and efficient scintillation characteristics.