Abstract
The effects of Li substitution on K in (Na0.53K0.47-x Li x )NbO3 (NKLN) ceramics prepared by a solid state process were studied at 0 ≤ x ≤ 0.09. Phase purity was maintained up to x = 0.04, then a secondary phase started emerging. With increasing Li substitution, partial melting appeared to occur and grain size increased. Polymorphic phase transition (PPT) temperatures, T O-T between orthorhombic and tetragonal phases and T C between tetragonal and cubic phases, were significantly affected by Li substitution. With increasing x, T O-T decreased while T C increased extending the tetragonal phase region. The highest d 33 of 220 pC/N was obtained at x = 0.07 mol at which high apparent density of the sintered pellets was obtained despite the formation of an impurity phase.
Acknowledgment
This work was supported by the National Research Foundation of Korea (NRF) Grant funded by the Korean Government (MEST) (2011-0030805). This research was also supported by Basic Science Research Program through the National Research Foundation (NRF) of Korea funded by the Ministry of Education, Science and Technology (2011-0026389).