The recent technological developments [1] make it possible to treat the crystals of zirconium dioxide partially stabilized with yttrium oxide (Y-PSZC) as modern structural materials that can fred several applications in technology and medicine. These crystals can be obtained using the same raw materials as those used for obtaining partially stabilized and tetragonal polycrystalline ceramics (but without stringent specifications with respect to the morphology and the particle size of the original powder). They are used effectively up to a temperature of 1500-1600~ [2] owing to their continuous structure (without grain boundaries and the undesirable consequences due to their presence) and the other features distinguishing them from the conventional materials.However, Y-PSZC has not been studied extensively (in particular, in our countries). The investigations carried out on this material aim mainly at understanding the behavior of the crystals containing only yttrium oxide as a stabilizing additive.The situation regarding the research on the effect of the additives is far from being satisfactory. It is known that the addition of a small quantity (0.01-0.5%*) of the rare-earth oxides (for example, Tb203) in a specific range of concentration of the stabilizing oxide does not change the phase composition of the crystals but can change their properties [3, 4]. In view of this, we continued our studies on the effect of the additives on the mechanical behavior of the aforementioned crystals [5, 6] and investigated the behavior of the crystals of Y-PSZC containing terbium oxide that were synthesized for the ftrst time under experimental-industrial conditions. Materials and Experimental Procedure. Studies were carried out using the crystals grown in a cold container (CC) according to the method described elsewhere [11. In order to prepare charges for obtaining single crystals, we used the "purity" grade zirconium dioxide powder (containing ZrO 2 > 99%), the ItO-Lyum grade (purity 99.99%) Y203 powder, and the TbO-3 grade (purity 99.9%) TbzO 3 powder.When selecting specimens, we took into account the nature of the temperature variation along the diameter of CC that owes to the specific features of heat liberation in the melt located in a high-frequency field [7] and leads to different conditions of crystal growth at the center of this container and in the vicinity of its cooled walls. As a result of this, columnar crystals having the same cross sectional area at the beginning and the end of their growth form in the central zone (zone 1) extending over approximately 0.25D c (D e is the diameter of CC). In zone 2 (measuring 0.1-0.15D c) adjoining the walls of CC, crystals having 2-3 times larger transverse dimensions towards the end of their growth than at the beginning of growth and elongated in the direction of the walls are developed. In the intermediate zone (zone 3), the cross section of these crystalline blocks is either uniform or nonuniform. Besides this, during the emergence of the crystals from the zone of growth,...

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