Synthesis of a sodium niobate-based lead-free piezoelectric ceramic using a submicron-sized NaNbO3 powder

A submicron-sized NaNbO
₃
fine powder was successfully synthesized using a molten salt method. The sinterability of the NaNbO
₃
powder was remarkably improved compared to that of NaNbO
₃
prepared using the conventional solid-state reaction method. A 0.9NaNbO
₃
-0.1BaTiO
₃
ceramic was then prepared a using mixture of submicron-sized NaNbO
₃
and BaTiO
₃
powders. It was found that the mixture reacted at approximately 1000°C to a single-phase, tetragonal perovskite structure with a submicron grain size. The calculated electromechanical coupling factor (k
_p
) and the piezoelectric constant (d
₃₃
) measured using a d
₃₃
meter were 0.34 and 160 pC/N, respectively.