Dielectric and piezoelectric properties of sodium potassium niobate-based ceramics sintered in microwave furnace

In this work K0.48Na0.48Li0.04Nb0.96Ta0.04O3 ceramics modified with different amounts of SrTiO3 (from 0 to 10 mol %) were fabricated via conventional sintering as well as microwave sintering. Microstructure, dielectric and piezoelectric properties of sintered ceramics via both methods, were investigated and compared. Microstructure of samples revealed that microwave sintering results in denser, more fine and uniform microstructure compared to conventional sintering. Ceramics containing more than 3% SrTiO3 showed relaxor behavior. Moreover microwave sintering enhanced relaxor behavior. Since ceramics containing 1% SrTiO3 had orthorhombic and tetragonal structures simultaneously, these ceramics showed maximum piezoelectric constant. Moreover microwave sintered ceramics due to denser as well as closer composition to stoichiometry, reveled higher piezoelectric constant compared to conventional sintered ones.