Synthesis of La1-xCox Fe1-yCryO3 nano crystallites for enhanced ferroelectric, magnetic and photocatalytic properties

Abstract

Cobalt (Co) and chromium (Cr) doped lanthanum ortho-ferrite with a composition of La1-xCox Fe1-yCryO3 (x, y = 0.0, 0.15, 0.30, 0.45, 0.60, 0.75) were fabricated by micro-emulsion route. The effect of Co2+ and Cr3+ cation substitution on the structural and dielectric properties was explored by XRD, FTIR, AFM, magnetic analysis, dielectric and ferroelectric measurements, which showed orthorhombic geometry. Various parameters like lattice constant (a, b, c), bulk density (ρm), X-ray density (ρx), porosity (P) and crystalline size were determined. By increasing dopant contents, the saturation magnetization was also increased and exhibited ferromagnetic property and LaFeO3 exhibits anti-ferromagnetism. The maximum value of magnetic saturation (0.841 emu) and Mr (0.420 emu) was found for highly substituted La0.40Co0.60Fe0.40Cr0.60O3 form. Through polarization electric (P-E) loops, the ferroelectric nature of fabricated nanoparticles was confirmed. It was observed that the values of dielectric constant (ɛ́ ), dielectric loss (ɛ ̋ ) and loss tangent (tanᵟ) were decreased with increasing the frequency. In addition, the conductivity is continuously increased with increasing frequency as well as dopant concentration. Furthermore, photocatalytic efficiency was evaluated by degrading methyl orange (MO) dye under UV irradiation and it was found that most substituted nanomaterial La0.40 Co0.60Fe0.40Cr0.60O3 exhibited maximum degradation of 91.01% of MO dye. Results revealed that the lanthanum ortho-ferrite properties can be tuned by doping with Cr and Co for practical applications in different filed since the ferroelectric, magnetic and photocatalytic properties were changed as a function of dopant concentration.