Effective dielectric properties of Cement/Ba0.06(Na0.5Bi0.5)0.94TiO3 composites: A comparative approach

Lead-free ceramic powder of a morphotropic phase boundary composition Ba0.06(Na0.5Bi0.5)0.94TiO3 (BNBT) was prepared from a solid-state synthesis route. The cement-ceramic (1−ϕ)cement/ϕBNBT; 0 ≤ ϕ 1.0 composites were fabricated. The filler concentration-dependent values of the bulk density and real part of complex permittivity showed an increasing trend of variation while the apparent porosity and imaginary part of complex permittivity followed a decreasing trend. In order to test the acceptability of dielectric mixture equations of the inclusion material in the mixture, five such equations have been chosen. The Bruggeman, and Rother-Lichtenecker equations showed their coherence with minimal deviation from the experimental results of the real part of complex permittivity for the entire measurement range of volume fractions. Also, a first-order exponential growth/decay type of mathematical model was suggested which could fit the experimental data excellently well (r2 > 0.97).