MnO_2 첨가량에 따른 비납계 (Na,K,Li)(Nb,Sb,Ta)O_3 세라믹스의 전기적특성

Abstract

Electrical properties and microstructure were investigated on the effects of MnO_2 and the lead-free (Na_0.44K_0.52Li_0.04)(Nb_0.83Sb_0.07T_a0.1)O_3 ceramics with the addition of MnO_2 were fabricated by a conventional mixed oxide method. A gradual change in the crystal and microstructure was observed with the increase of MnO_2 addition. For the NKN-LST-xmol%MnO_2 sintered at 1100℃, bulk density increased with the addition of MnO_2 and showed maximum value at addition 1.0mol% of MnO_2. Curie temperature of the NKN-LST ceramics slightly decreased with adding MnO_2. The dielectric constant, piezoelectric constant (d_33) and electromechanical coupling factor (k_p) increased below 0.25mol% of MnO_2 addition, which might be due to the increase in density. The high piezoelectric properties = 145 pC/N, electromechanical coupling factor = 0.421 and dielectric constant = 2883 were obtained for the NKN-LST-0.25mol%MnO_2 sintered at 1100℃ for 4h.