Enhancement of dielectric properties and microstructure control of BaTiO3 by seed-induced solid-state synthesis

Abstract

Multilayer ceramic capacitor (MLCC) is a key passive component that maintains stable current flow and controls electromagnetic interference between components in the safety and protective electronics in automobiles. Defects that exist in BaTiO3 manufactured by hydrothermal synthesis make it unsuitable for use as raw material for the production of MLCCs for the automotive industry, where reliability is important. In this study, a solid-state synthetic seed process for the development of solid-state BaTiO3 powder with high crystallinity is demonstrated. In this process, before initiation of the solid-state synthesis of BaCO3 and TiO2, a fine nucleation site to synthesize BaTiO3 dielectric ceramic powder with uniform composition, high crystallinity, and fine size was formed. The addition of 25 wt% of 50 nm-sized BaTiO3 seeds to induce homogeneous synthesis between precursors facilitated low-temperature solid-state synthesis and BaTiO3 synthesis with improved crystallinity. Particularly, the homogeneous nucleation was effective in facilitating the atomization of grains after sintering, and thus the dielectric properties were greatly improved. The results of this study establish the effectiveness of the solid-state synthesis process in improving the properties of BaTiO3 dielectric powder for use in the manufacture of MLCCs.