New Nonstoichiometric Ferroelectric Oxyfluoride Phases Derived From LiNbO3 and LiTaO3.

Article abstract of DOI:10.1016/0022-5088(88)90077-X

Six new non-stoichiometric oxyfluoride phases, the compositions of which are related to LiMo//3 (M EQUVLNT Nb, Ta), have been prepared. They belong either to the LiNbO//3-LiF-NbO//2F or the LiTaO//3-LiF-TaO//2F system. Thermal and dielectric measurements have shown each composition to present a ferroelectric-paraelectric transition. The Curie temperature T//C increases with cationic excess and decreases with cationic deficit. The F-O substitution has only a small influence on T//C.