Colossal dielectric response, relaxation mechanism and multiferroic properties of (Ba1-xSmx)(Ti1-xFex)O3 (0.0 ≤ x ≤ 0.5)

[Display omitted] •Colossal dielectric constant (CDC) observed for compositions x = 0.3, 0.4 and 0.5.•CDC originates due to the formation of internal barrier layer capacitor.•CDC in wide temperature range explained on the basis of multiple phase transition.•Relaxation mechanism analyzed from the Cole-Cole plot and Bode plot. Structural, microstructural, dielectric, multiferroic characteristics and relaxation mechanisms of (Ba1-xSmx)(Ti1-xFex)O3 samples with varrying compositions (x = 0.0–0.5) are reported in the present article. Standard crystal data and the Rietveld refinement results suggest tetragonal structure for all the compositions similar to the pure BaTiO3. SEM, EDX and color mapping are used for the analysis of microstructural, compositional and elemental study. Impedance analysis is carried out using Nyquist plot. Relaxation mechanisms are analyzed from the complex permittivity Cole-Cole plot and the Bode plot. Colossal dielectric constant was observed over a wide temperature range for compositions x = 0.3, 0.4 and 0.5 due to the formation of internal barrier layer capacitors and the ferroelectric-paraelectric transitions of BaTiO3 and magnetic transitions of SmFeO3. The colossal dielectric response of these compositions makes them suitable for potential applications in microelectronic devices such as dynamic random access memory (DRAM) and on-chip capacitors.