Effect of charge compensation change on the crystal structure, grain growth behavior, and dielectric properties in the La2O3-doped BaTiO3 system with MnCO3 addition

Abstract

The effect of MnCO3 additions on crystal structure, grain growth behavior, and dielectric properties were studied in the La2O3-doped BaTiO3 system. La2O3-doped BaTiO3 powders were prepared by conventional solid-state reaction routes and then after the addition of MnCO3, the powder compacts were sintered at 1250 degrees C in air. The tetragonality (c/a) of the samples increased with the amount of up to 0.5 mol% MnCO3 and then decreased above 0.5 mol%. The 3D grain shape became more spherical polygons with increasing amounts of MnCO3. The grain growth behavior changed from suppressed growth to abnormal grain growth and finally normal grain growth with increasing amounts of MnCO3 when the powder compacts were sintered. The correlation between the grain growth behavior and the grain shape change is discussed from the perspective of two-dimensional nucleation grain growth theory. Further, the dielectric properties are discussed in terms of the crystal structure, microstructural control, and charge compensation. (c) 2022 Published by Elsevier B.V.