Structural and electrical properties of lead reduced lanthanum modified BiFeO₃–PbTiO₃ solid solution

Lanthanum modified binary electronic systems of BiFeO₃ (BFO) and PbTiO₃ (PT) in different molar ratios with reduced lead (Pb) content have been synthesized by using a high-temperature solid-state reaction technique. Detailed studies of structural, morphological and electrical properties of the prepared solid solutions [(Pb_1−xBi_0.5xLa_0.5x)(Fe_xTi_1−x)O₃ with x = 0.1, 0.3, 0.5 and 0.7] have provided some interesting findings on structure-properties relationship. An abrupt change is observed in the structure of the solid solution from tetragonal to rhombohedral with the increase of La concentration. The micro-structural analysis reveals that the grain size of the system reduces on increasing La concentration of the prepared electronic system. The reduction of Pb concentration not only advances the dielectric response of lanthanum modified BiFeO₃–PbTiO₃ electronic material but also suppresses the toxic behavior of the material. For higher concentration of La, the remnant polarization is observed to be minimum. The impedance studies exhibit the presence of grain and grain boundary effects, and existence of a negative temperature coefficient of resistance (NTCR) in the material. The ac conductivity increases with increase in frequency in the low-temperature region for all the materials. It is observed that the prepared electronic materials obey the non-exponential type of conductivity relaxation.