Structural, Optical, and Multiferroic Properties of Yttrium (Y3+)-Substituted BiFeO3 Nanostructures

Abstract

Nanoparticles of Bi1-xYxFeO3 (x = 0.0, 0.1, 0.15, 0.2) were synthesized by sol-gel pursued auto-combustion route. X-ray diffraction (XRD) pattern was recorded for analysis of the phase formation of pristine BiFeO3 (BFO) and Y3+-substituted samples. A systematic decrease in crystallite size with increasing concentration of Y3+ was observed by XRD and W-H plot. FESEM micrograph demonstrated clearly that the average grain size is decreased with increasing Y3+ ion concentration. Compositional analysis was carried out by EDS. Optical properties of the developed nanoparticles were examined by diffuse reflectance spectroscopy; it is observed that optical band gap decreases with increase in Y3+ ion concentration. Vibrating sample magnetometer (VSM) analysis revealed weak ferromagnetic behavior for pristine BFO. The ferromagnetic behavior has been enhanced with increasing concentration of Y3+ ions in BFO. Temperature dependence of dielectric constant shows an anomaly near the antiferromagnetic transition temperature in the developed materials that revealed the existence of magnetoelectric coupling in all the samples. Improved ferroelectric property has been observed by virtue of enhancement in the polarization of all substituted samples. Variation of electric field–guided strain with applied electric field has shown asymmetric behavior for samples x ≤ 0.15 and symmetric loop has been observed for x = 0.2 with the highest peak to peak strain value which makes it active material for electronic and magnetic devices.