Physicochemical, dielectric, and piezoelectric properties and conductivity of LiNb[O.sub.3] : ZnO crystals

The physicochemical characteristics of the crystal-melt system during the growth of LiNb[O.sub.3] : ZnO crystals have been investigated in the range of impurity concentration [ZnO] in the melt of 4.02-8.91 mol %. The threshold impurity concentration corresponding to a significant change in the formation conditions and structure of LiNb[O.sub.3] : ZnO crystals is refined ([ZnO] = 6.76 mol % in the melt). The dielectric and piezoelectric properties and conductivity of multidomain LiNb[O.sub.3] : ZnO crystals have been analyzed. The occurrence of a significant spontaneous increase in the unipolarity upon high-temperature annealing has only been shown to be typical of LiNb[O.sub.3] : ZnO crystals grown from melts in the near-threshold concentration range (~5.4 < [ZnO] [less than or equal to] 6.76 mol % in the melt). This effect is accompanied by a large and reproducible increase in the static piezoelectric coefficient [d.sub.333]. The value of the piezoelectric-coefficient jump A[d.sub.333] linearly increases with an increase in the specific-conductivity jump [DELTA][sigma] near the temperature T* [approximately equal to] 800 K. DOI: 10.1134/S1063784217010170