Enhanced dielectric and ferroelectric properties of 0.57(Bi,La)FeO3-0.43PbTiO3 multiferroic ceramics by the Ti substitution

The ceramics of 0.57(Bi_0.8La_0.2)(Fe_1xTi_x)O₃-0.43PbTiO₃ (BLFT-PT) for 0 les x les 0.15 have been synthesized by the solid state reaction method. BLFT-PT ceramics exhibit the dominant rhombohedral structure for x les 0.08, which transfer to the tetragonal phases with further increasing the Ti concentration. However, the second phases are detected for BLFT-PT of x ges 0.1. Upon using the Ti substitution, the ac (alternating current) conductivity sigma_ac of BLFT-PT ceramics is significantly reduced at the elevated temperatures. The remnant polarization P_r and piezoelectric constant d₃₃ of BLFT-PT are enhanced by the Ti substitution, reaching the maximum of P_r = 46 muC/cm² and d₃₃ = 262 pC/N for x = 0.05. Our results indicate that BLFT-PT is an alternative multiferroic candidate with excellent piezoelectric properties.