Synergistic effect enhanced the room temperature dielectric constant and wide temperature stability in BaTiO3 based-ITO composite ceramics

Barium titanate (BaTiO 3 , BT) is an excellent electronic material with great application for multilayer ceramic capacitors (MLCCs). In this work, BaTiO 3 based- In 2 O 3 ·SnO 2 (ITO) composite ceramics were synthesized via solid-state reaction method, which optimizes the dielectric properties of the BT-based materials through the atomic scale to the micro-nano scale. The BaTiO 3 based material is composited with ITO to construct the percolation capacitor, which greatly enhances the room-temperature dielectric constant of BT-based materials. Among them, the grain sizes of BT-based material and ITO are 552–581 nm and 483–553 nm, respectively. In addition, BT-based materials are obtained after optimization of the rare earth ion doping effect and the “core-shell” effect. The substitutional defects generated by the rare earth Gd 3+ ions produce abundant positive and negative charges in the core phase BT, which also leads to the optimization of the room-temperature permittivity. Meanwhile, the “core-shell” structure produced by niobate-encapsulated BT-based material with doped Gd 3+ ions further enhances the dielectric-temperature stability of BT-based materials. Based on the synergy of rare earth ion doping effect, “core-shell” effect, and percolation effect, Ba 0.9985 Gd 0.0015 @(Ni,Mn)Nb 2 O 6 -ITO (BGT@(N,M)NO-ITO) percolation composite ceramics have a room temperature dielectric constant as high as 7184 with a dielectric low loss of 3.8 %, and the temperature stability meets X8R. In this work, the BGT@(N,M)NO-ITO percolation composite ceramics with excellent dielectric properties are expected to be used in MLCCs, which further broadens the application of BT-based materials.