Effect of MnO2 addition on the structure and electric properties of (Ba0.94Ca0.06)(Ti0.9Sn0.1)O3 ceramics

The (Ba0.94Ca0.06)(Ti0.9Sn0.1)O3 (BCTS) ceramics with pure perovskite structure were prepared by conventional solid-state reaction route with the addition of 0-0.8 mol% MnO2. The crystal structure, microstructure, and electric properties were investigated systematically. X-ray diffraction patterns showed that the addition of MnO2 changed the ratio of the coexistence of orthorhombic and tetragonal phases, which had apparent influences on the piezoelectric properties of ceramics. When the addition amount is 0.2 mol%, the average grain size increases from ~41.88-52.24 µm, and, however, the average grain size decreases with further addition > 0.2 mol%. A good combination of properties and performance could be achieved with the addition of 0.4 mol% MnO2. The mechanical quality factor Qm, dielectric loss tanδ, piezoelectric constant d33, and planar electromechanical coefficient kp measured are 216, 0.011, 578 pC/N, and 0.39, respectively. Therefore, results of this study suggest that the BCTS-Mn ceramics synthesized could exhibit a great potential for piezoelectric component applications.