The key aim of this paper is to study the presence effect of LiO impurity phases in Li₂ZrO₃ ceramics on the resistance to helium swelling and structural degradation during implanted helium accumulation in the near-surface layer structure. The hypothesis put forward is based on a number of scientific papers, in which it was reported that the presence of two or more phases in lithium-containing ceramics led to a decrease in the rate of radiation damage and gas swelling due to the presence of additional interfacial boundaries that prevent the point defect accumulation. As a result of the evaluation of the crystal structure deformation, it was found that the presence of the LiO impurity phase in the structure of Li₂ZrO₃ ceramics led to a threefold decrease in the deformation of the crystal lattice due to helium swelling at doses of 5 × 10¹⁷–5 × 10¹⁸ ion/cm². At the same time, the nature of the crystal lattice deformation for different ceramic types is different: in the case of Li₂ZrO₃ ceramics, an anisotropic distortion of the crystal structure is observed, in the case of Li₂ZrO₃/LiO ceramics, the crystal lattice deformation has an isotropic nature.

The article is dedicated to the study of the phase formation processes in Li₂ZrO₃ ceramics obtained by the method of solid phase synthesis. Interest in these types of ceramics is due to their great potential for use as blanket materials in thermonuclear reactors, as well as being one of the candidates for tritium breeder materials. Analysis of the morphological features of the synthesized ceramics depending on the annealing temperature showed that the average grain size is 90–110 nm; meanwhile the degree of homogeneity is more than 90% according to electronic image data processing results. The temperature dependences of changes in the structural and conducting characteristics, as well as the phase transformation dynamics, have been established. It has been determined that a change in the phase composition by displacing the impurity LiO and ZrO₂ phases results in the compaction of ceramics, as well as a decrease in their porosity. These structural changes are due to the displacement of LiO and ZrO₂ impurity phases from the ceramic structure and their transformation into the Li₂ZrO₃ phase. During research, the following phase transformations that directly depend on the annealing temperature were established: LiO/ZrO₂/Li₂ZrO₃ → LiO/Li₂ZrO₃ → Li₂ZrO₃. During analysis of the obtained current-voltage characteristics, depending on the annealing temperature, it was discovered that the formation of the Li₂ZrO₃ ordered phase in the structure results in a rise in resistance by three orders of magnitude, which indicates the dielectric nature of the ceramics.

The study examines the influence of variations in the compositions of components for the production of lithium-containing ceramics based on lithium metazirconate obtained by the method of mechanochemical grinding and subsequent thermal sintering. For component variation, two compositions were used, consisting of zirconium dioxide (ZrO₂) and two distinct types of lithium-containing materials: lithium perchlorate (LiClO₄·3H₂O) and lithium carbonate (Li₂CO₃). Adjusting the concentration of these components allowed for the production of two-phase ceramics with varying levels of impurity phases. Using X-ray phase analysis methods, it was determined that the use of LiClO₄·3H₂O results in the formation of a monoclinic phase, Li₂ZrO₃, with impurity inclusions in the orthorhombic phase, LiO₂. On the other hand, when Li₂CO₃ is used, the resulting ceramics comprise a mixture of two phases, Li₂ZrO₃ and Li₆Zr₂O₇. During the studies, it was established that the formation of impurity inclusions in the composition of ceramics leads to an increase in the stability of strength properties with varying mechanical test conditions, as well as stabilization of thermophysical parameters and a decrease in thermal expansion during long-term high-temperature tests. It has been established that in the case of two-phase ceramics Li₂ZrO₃/Li₆Zr₂O₇ in which the dominance of the Li₆Zr₂O₇ phase is observed during high-temperature mechanical tests, a more pronounced decrease in resistance to cracking is observed, due to thermal expansion of the crystal lattice.

The work is devoted to the study of technology that can be used to obtain lithium-containing ceramics of the Li_2+4xZr_4−xO₃ type using the method of solid-phase synthesis combined with thermal annealing at a temperature of 1500 °C. A distinctive feature of this work is the preparation of pure Li₂ZrO₃ ceramics with a high structural ordering degree (more than 88%) and density (95–97% of the theoretical density). During the study, it was found that a change in the content of initial components for synthesis does not lead to the formation of new phase inclusions; however, an increase in the LiClO₄·3H₂O and ZrO₂ components leads to changes in the size of crystallites and dislocation density, which lead to the strengthening of ceramics to external mechanical influences. The results of the measurements of thermophysical characteristics made it possible to establish that the compaction of ceramics and a decrease in porosity lead to an increase in the thermal conductivity coefficient of 3–7%.