Study of the Solid Solution (Ba1-xSrx)2SmTi2Nb3O15 (x = 0-1)

Abstract

The compounds (Ba1-xSrx)2SmTi2Nb3O15 were synthesized via the solid-state method and characterized by X-ray diffraction (XRD) and impedance spectroscopy. The crystal structure is tetragonal, belonging to the P4bm space group. The lattice parameters (a = b, c, and V) decrease with increasing Sr substitution. Both the theoretical and experimental densities decrease as the Sr content rises. Impedance measurements show that all the compounds exhibit ferroelectric behavior, with the Curie temperature (Tc) decreasing from 332 °C (100% Sr) to 269.44 °C (100% Ba). Furthermore, impedance analysis allowed the determination of an equivalent electrical circuit. The AC conductivity spectra of the studied compounds follow Jonscher's power law. The relaxation process in the material is non-Debye type, and the temperature coefficient of resistance (NTCR) in the material is negative.