Dielectric and electromechanical properties of lead-free BiFeO3–BaTiO3–LiTaO3 ceramics

In this study, lead-free perovskite solid solution ceramics of MnO2 (0.6 mol.%) and CuO (0.4 mol.%) mixed (1–x)(0.675BiFeO3 – 0.325BaTiO3) – xLiTaO3 (BFBT–xLT+MC, with x = 0.000 ≤ x ≤ 0.020) were prepared by... [ view full abstract ]

In this study, lead-free perovskite solid solution ceramics of MnO₂ (0.6 mol.%) and CuO (0.4 mol.%) mixed (1–x)(0.675BiFeO₃ – 0.325BaTiO₃) – xLiTaO₃ (BFBT–xLT+MC, with x = 0.000 ≤ x ≤ 0.020) were prepared by solid-state reaction method (followed by quenching process). The effect of LT-content in BFBT+MC system on the crystal structure, morphology, dielectric, ferroelectric and piezoelectric properties were investigated. XRD patterns confirms that, LT-modification exerts no significant effect on the crystal structure of the BFBT+MC ceramics, while micrographs showed similar morphology with dense and compact microstructures. The dielectric, ferroelectric, and piezoelectric properties were improved by the optimum addition of LT-modifier in BFBT+MC system. When LT is incorporated in BFBT+MC ceramics, a diffused, still, visible T_C was observed. The T_C for BFBT–0.01LT+MC sample was relatively sharp which become more diffuse with increasing amount of LT concentration. At the same composition, the dynamic piezoelectric constant (d^*₃₃ = S_max/E_max) substantial improved (up to 70 %) in comparison with the host BFBT+MC system.