Nonlinear dielectric properties of BaTiO3 - Silver composites: The role of microstructure

V. A. Lukacs, I. Turcana, L. Padurariu, L. Curecheriu, A. Cernescu, G. Stoian, C. E. Ciomaga, F. Tufescu, N. Lupu and L. Mitoseriu

Journal of Alloys and Compounds 817,153336 (2020)
A comprehensive insight into the structure-properties relationship of Ag–BaTiO3 composite ceramics was realized by combining modeling tools with a detailed analysis of macroscopic electrical properties in relationship with microstructural peculiarities. Di-phase Ag–BaTiO3 ceramics (0–5 vol% Ag) with room temperature permittivity values between 2740 and 7085 and low dielectric loss (tan δ < 4%) have been investigated. These composites show an enhancement of tunability from 2 for pure BaTiO3 ceramic to 4 in case of 5 vol% silver addition (at 21.6 kV/cm). The Finite Element Analysis demonstrated that the enhancement of tunability is related to the silver melting during sintering, causing peculiar microstructures, with local percolation channels in the composite’s volume.