Piezoelectric Properties of Mn-modified Na0.5Bi2.5Nb2O9 for High Temperature Applications

Bismuth layer-structured ferroelectric ceramics Na0.5Bi2.5Nb2O9(NBN+xmol% MnCO3, 0≤x≤10.0) were synthesized by traditional solid state reaction. The effects of Mn addition on the microstructure and electrical properties of ceramics were investigated in detail. The results showed that all the ceramic samples were single-phase ferroelectrics with high Curie points (Tc≥700 With the addition of MnCO3, the mechanical quality factor, piezoelectric activity and electromechanical properties of Na0.5Bi2.5Nb2O9-based ceramics are enhanced significantly. Besides, the NBN+8.0mol% MnCO3 ceramic exhibits the optimum electrical properties: tanδ=0.749%, d33=20 pC/N, Qm=3120, kp=12.37%, kt=21.09%, Pr=7.01 μC/cm2. After annealing at 700 the d33 value of NBN+8.0mol% MnCO3 ceramic remains 75%(~15 pC/N), which indicates that this ceramic is a promising material for high temperature applications.