MnO2첨가량에 따른 비납계 (Na,K,Li)(Nb,Sb,Ta)O3세라믹스의 전기적특성

Abstract

Electrical properties and microstructure were investigated on the effects of MnO₂ and the lead-free (Na<SUB>0.44</SUB>K<SUB>0.52</SUB>Li<SUB>0.04</SUB>)(Nb<SUB>0.83</SUB>Sb<SUB>0.07</SUB>Ta<SUB>0.1</SUB>)O₃ ceramics with the addition of MnO₂ were fabricated by a conventional mixed oxide method. A gradual change in the crystal and microstructure was observed with the increase of MnO₂ addition. For the NKN-LST-xmol%MnO₂ sintered at 1100℃, bulk density increased with the addition of MnO₂ and showed maximum value at addition 1.0mol% of MnO₂. Curie temperature of the NKN-LST ceramics slightly decreased with adding MnO₂. The dielectric constant, piezoelectric constant (d₃₃) and electromechanical coupling factor (k<SUB>p</SUB>) increased below 0.25mol% of MnO₂ 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%MnO₂ sintered at 1100℃ for 4h.