Modifying electric and multiferroic properties of lead-free 0.7BFO-0.3BTO ceramics via Sm and Ga co-doping

Abstract

Polycrystalline lead-free composite ceramics composed of 0.7Bi1-xSmxFe0.95Ga0.05O3−0.3BaTiO3 (BSxFG-BT) with varying doping concentration of x (0.025, 0.05, 0.10, 0.15, and 0.20) were synthesized. This study comprehensively explores the influence of co-doping Samarium (Sm) and Gallium (Ga) on the microstructures, spectral properties, electrical characteristics, and multiferroic behaviour within the 0.7BiFeO3−0.3BaTiO3 system. These composite ceramics exhibited coexistence of R (rhombohedral) and T (tetragonal) phases, characterized by the space groups R3c and P4mm, respectively. The XRD and AFM results show that the Sm and Ga co-doping influenced the crystal structure as well as grain size of BSxFG-BT ceramics. Raman spectroscopy was used to analyze the positions of the phonon modes. High dielectric constant with high Curie temperature of 550 °C were obtained. The impact of grain and grain boundary on the capacitance and resistance in the ceramics was investigated utilizing Z-view software and high magnitude of bulk resistance was obtained for dopant value x = 0.20 at 300 °C. Enhanced multiferroic properties, remanent magnetisation Mr = 0.051 emu g−1 with coercive field (Hc) = 6450 Oe and remanent polarization Pr = 10.98 μC cm−2 with coercive filed Ec = 14.73 kV cm−1 were obtained for x = 0.20.