Anomalous dielectric and piezoelectric properties and electrical conductivity of heavily doped LiNbO3:Zn crystals

Abstract

In LiNbO₃:Zn crystals with near-threshold doping levels ( 4.5–4.7 mol % Zn), high-temperature measurements and high-temperature annealing under short-circuit conditions lead to considerable changes in spontaneous unipolarity. The considerable changes in spontaneous unipolarity are accompanied by well-defined low-frequency dielectric dispersion and sharp anomalies in temperature dependences of electrical conductivity and dielectric permittivity. As a result, the piezoelectric modulus d₃₃₃ increases to a level approaching the highest values reported in the literature for single-domain nominally pure LiNbO₃ crystals.