Processing, dielectric and impedance spectroscopy of lead free BaTiO3-BiFeO3-CaSnO3

Highlights: • The cheap cost synthesis of BTO-BFO-CSO and best performance is evaluated. • Dielectric properties with respect to temperature and frequency is investigated. • Nyquist plots relate about contributions of grain with NTCR behavior. • A well defined relaxation mechanism was identified by modulus analysis. The paper presents the fabrication and characterization of structural and electrical properties of an electronic composite of three perovskites: BaTiO_3, BiFeO₃ and CaSnO₃ in a fixed ratio of 80/13/07 (i.e., 0.80(BaTiO₃)-0.13(BiFeO₃)-0.07(CaSnO₃) (referred as BTO-BFO-CSO-7)) using standard experimental techniques. Analysis of room temperature X-ray diffraction spectra helps to determine the crystal system and unit cell dimensions (lattice parameters) of the sample. The dielectric and impedance spectroscopy was used to study the resistive (impedance, complex electrical modulus and electrical transport properties) and insulating (dielectric) characteristics of the prepared electronic material at various frequencies (10²–10⁶ Hz) and temperatures (20–450 °C). Study of the Nyquist plot confirms the presence of temperature dependent bulk (grain) effect only and negative temperature coefficient resistance in the BTO-BFO-CSO-7 composite. Analysis of conductivity spectra reveals that the charge transfer by hopping contributes to the electrical transport process. The dielectric relaxation of the sample is studied using complex modulus spectra. This study also helps to understand the mechanism of the electrical transport process, which depicts a non-Debye type of conductivity relaxation. The magnetic hysteresis loop (M − H) shows a remanent magnetization of 0.031 emu/g.