This study investigates the effect of MnO2 and CuO as acceptor additives on the microstructure and piezoelectric properties of 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3-0.04BaZrO3, which has a rhombohedral-tetragonal phase boundary composition. MnO2 and CuO-added 0.96(K0.5Na0.5)0.95Li0.05Nb0.93Sb0.07O3-0.04BaZrO3 ceramics sintered at a relatively low temperature of 1020 oC show a pure perovskite phase with no secondary phase. As the addition of MnO2 and CuO increases, the sintered density and grain size of the resulting ceramics increases. Due to the difference in the amount of oxygen vacancies produced by B-site substitution, Cu ion doping is more effective for uniform grain growth than Mn ion doping. The formation of oxygen vacancies due to B-site substitution of Cu or Mn ions results in a hardening effect via ferroelectric domain pinning, leading to a reduction in the piezoelectric charge coefficient and improvement of the mechanical quality factor. For the same amount of additive, the addition of CuO is more advantageous for obtaining a high mechanical quality factor than the addition of MnO2.

Abstract
 1. Introduction
 2. Experimental Procedure
 3. Result and Discussion
 4. Conclusion
 References

• Kyung-Hoon Cho(School of Materials Science and Engineering, Kumoh National Institute of Technology) Corresponding author