Effects of lanthanum dopants on dielectric and multiferroic properties of BiFeO3–BaTiO3 ceramics

Abstract

La2O3 substituted polycrystalline 0.56BiFeO3-0.44BaTiO3 ceramics have been prepared through the conventional solid-state reaction process. The crystal structure, dielectric, magnetic and impedance spectroscopic properties of the prepared materials have been investigated. X-ray diffraction (XRD) technique suggests the tetragonal (p4/mmm) phase structure of the prepared ceramics. The SEM exhibits the growth of compact compound with uniform distribution of grains. The Substitution of La gradually reduces the transition temperature which becomes near ∼134°C for the highest concentration La doping. Impedance spectroscopic measurements confirm a non-Debye type relaxation phenomenon and calculated grain resistance (Rg) and grain capacitance (cg) through Nyquist plot. The variation of conductivity with temperature reveals the negative temperature coefficient of resistance (NTCR). The activation energy (Ea)has been estimated from temperature dependence ac conductivity. The P-E and M − H curves of the materials studied at room temperature indicate the multiferroic nature of the materials. The energy storage density calculated from the P-E curve and the obtained remnant magnetization from the M − H curve increase significantly due to La substitution reveals that the La-doped BFO-BTO ceramics have enhanced multiferroicity.