Structural, optical and enhanced multiferroic properties of La/Cr co-substituted BiFeO3 nanostructures

Abstract

We have synthesized BiFeO3 (BFO) and Bi0.5La0.5Fe1−xCrxO3 (0 ≤ x ≤ 0.06) samples via sol–gel process with the objective to explore the influence of La/Cr co-doping on the structural, optical, dielectric and multiferroic properties of BFO. Rietveld refinement analysis and Raman active modes affirm single-phase and rhombohedral crystal structure of the samples in R3c space group. The UV–visible-DRS data reveal a systematic reduction of the bandgap and increase in the Urbach energy (Eu) with the increase of La/Cr content in BFO matrix. The temperature-dependent dielectric measurements divulge that the BFO has the highest dielectric constant, and relaxation peak shifts with the rise in frequency that proposes the possibility of the thermally activated relaxation mechanism which also supported through the Vogel–Fulcher model. The magnetic hysteresis (M–H) loops exhibit ferromagnetic nature of all the samples at room temperature except BFO. The P–E hysteresis loops display ferroelectric behavior with higher values of polarization and coercive field in the doped samples.