Influence of Eu3+ substitution on structural, magnetic and dielectric properties of Bi0.9La0.1FeO3

Abstract

Enhanced magneto-electrical (ME) properties of BiFeO3 multiferroics are attained by the modification of structural morphology that is essential for the possible applications in multifunctional devices like miniaturization. This study focused on the improvement of the magnetic and dielectric properties in an ideal BiFeO3 achieved by the gradually substitution of Eu3+in place of Fe3+ (B-site) with slight addition of La3+ replacing Bi3+ (A-Site). In this regards the composition Bi0.9La0.1Fe1-xEuxO3 (x = 0, 0.02, 0.05, 0.07, 0.10 and 0.15) were synthesized by solid state reaction method. XRD patterns indicate the samples crystallize with the normal distorted rhombohedral phase (R3c space group) and oxygen vacancies are significantly suppressed by the increase of Eu3+ amount. The lowest porosity (1.9%) is observed in the sample for x = 0.07. The crystallite sizes are increased due to 15% Eu doping. The average size of the grains are observed to be increased in the micrograph for Eu doping compared to the undoped one. The strongest absorbance peak around 560 cm−1 in FTIR spectroscopy for all the samples confirm the octahedral FeO6 bonding while a pair of feeble peaks around 370 cm−1 and 440 cm−1 confirm the existence of BiO6 octahedral phase adjacent with FeO6 group. The magnetic saturation (Ms) is 0.89 emu/g for the undoped Bi0.9La0.1FeO3 and Ms increases for Eu3+ substitution at the Fe-site of the compound. The maximum Ms (1.58 emu/g) is observed in the sample for x = 0.07. The permeability (μ) and permittivity (ε) are highly affected by the reformed structure with various grain sizes and porosities (%) which have been reported in this work. The composition for 7% Eu3+ doping shows an excellent matching between μ’ and ε’ (μ’/ε’=0.9) with lower magnetic loss (tanδμ = 0.0133) over the frequency range from 1 MHz to 100 MHz.