Effect of Bi2O3 Addition on the Physical and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3 -( Na0.5Bi0.5)TiO3 Ceramics
In this paper, the effects of Bi2O3 addition on the electrical and physical properties of 0.98(Na0.5K0.5)NbO3-0.02(Na0.5Bi0.5)TiO3 were investigated. The 0.98(Na0.5K0.5)NbO3 -0.02(Na0.5Bi0.5)TiO3 [0.98NKN-0.02NBT] ceramics with the addition of 0~0.5 wt% Bi2O3 have been prepared following the conventional mixed oxide process. X-ray diffraction analysis revealed that, during sintering, all of the (Na0.5Bi0.5)TiO3 diffuse into the lattice of ((Na0.5Bi0.5))NbO3 to form a solid solution, in which a orthorhombic phase with a perovskite structure was found. For 0.98NKN-0.02NBT ceramics by doping 0.1 wt% Bi2O3, the poled dielectric constant (K33T) and the electromechanical coupling coefficients of the planar mode kp reach 684 and 0.38, respectively, after sintering at 1100 °C for 3 h. Our results show that 0.98NKN-0.02NBT with the addition of 0.1 wt% Bi2O3 is a good lead-free piezoelectric ceramic.
C. H. Wang "Effect of Bi2O3 Addition on the Physical and Electrical Properties of Lead-Free (Na0.5K0.5)NbO3 -( Na0.5Bi0.5)TiO3 Ceramics", Advanced Materials Research, Vols. 311-313, pp. 1250-1253, 2011