For 0.95(Na 0.5K 0.5)NbO 3-0.05BaTiO 3 (0.95NKN-0.05BT) ceramics sintered at 1040-1075°C, abnormal grain growth occurred but the grain size decreased when the sintering temperature exceeded 1075°C. The dielectric constant (∈ 3 T/∈ 3), electromechanical coupling factor (k p), and piezoelectric constant (d 33) were considerably increased with increasing relative density and grain size. Evaporation of Na 2O deteriorated the piezoelectric properties by decreasing the resistivity. To minimize Na 2O evaporation, specimens were muffled with 0.95NKN-0.05BT powders during the sintering. Improved piezoelectric properties of d 33=225 pC/N, k p=36%, and ∈ 3 T∈ 3 = 1058 were obtained for specimen sintered at 1060°C for 2h with muffling.
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)