Abstract
Densified LiTaO 3 -type ceramics can be obtained by sintering at 900°C after the addition of MgF 2 or (MgF 2 + LiF) mixture. Partial hydrolysis of MgF 2 produces an MgO layer on top of the sample. Space charge polarization occurs at high temperatures between the MgO layer and the LiTaO 3 matrix, inducing a large dielectric constant predominating over the ferroelectric Curie peak of the sample. The TiO 2 dopant lowers the Curie temperature of the sample as the cation concentration increases. In addition, it is observed that substitution of Ta ions with Mg ions results in the formation of Ta 2 O 5 . © 1991.