Effect of Ba2+ ions substitution with Sr2+ ions on the dielectric properties of Ba1−xSrxTiO3 ceramic solid solution

The temperature dependences of the complex permittivity components ε′ and ε″ for Ba1−xSrxTiO3 (0.1 ≤ x ≤ 0.7) solid solution obtained by two-stage ceramic technology were investigated. Both components ε′ and ε″ pass through the pronounced maxima near the Curie point. A growth of the ε′ maximum with an increase in the concentration of Sr atoms is associated with a reduction in the average grain size and an increase in the volume fraction of the intergranular layer having a lower ε′ compared to a grain. The increase in the diffusion of the phase transition with the concentration of Sr atoms is due to the greater heterogeneity of the solid solution. Based on the dielectric data, temperature dependences of the local order parameter were plotted.