Extending the investigations on (Na0.sK0.5)NbO3-based solid solution for lead-free piezoelectric ceramics,this paper consider the complex solid-solution system (Na0.sK0.5)NbO3-Bi0.5(Na0.80K0.20)0.5TiO3 [NKN-BNKT].(Na0.5K0.5)NbO3 with 2 ～ 6 mol% Bi0.5(Na0.80K0.20)0.5TiO3 has been...