Effect of Y3+ and Co2+ co-doping on the structural, optical, magnetic and dielectric properties of LaFeO3 nanoparticles.

This study explores the comprehensive characterization of Y³⁺ and Co²⁺ co-substituted LaFeO₃ nanoparticles synthesized via the sol-gel auto-combustion method. The synthesized samples, La_1-xY_xFe_1-y Co_yO₃ (x = 0,0.10 and y = 0,0.03,0.05,0.07) were characterized by employing various techniques such as x-ray diffraction (XRD), Scanning Electron Microscopy (SEM) with EDX, Raman spectroscopy, UV-visible spectroscopy, and Vibrating Sample Magnetometry (VSM). The Raman and XRD analysis, supported by Rietveld refinement, provided conclusive evidence of a pure orthorhombic LaFeO₃ phase. Microstructural studies unveiled an agglomerate-type, irregular particle distribution, while EDX analysis confirmed the elemental composition. The XPS study gives evidence about the presence of both Fe²⁺ and Fe³⁺ oxidation states, and Co has a Co³⁺ oxidation state. UV-vis spectroscopy demonstrated enhanced visible light absorption, revealing a reduced bandgap with increasing doping percentages. VSM measurements exhibited M-H loops, substantiating the weak ferromagnetic nature of the materials. Moreover, these nanoparticles exhibit dielectric constants and low dielectric losses, making them suitable for use in devices for communication. Overall, these findings may offer valuable contributions to the understanding of nanomaterial characteristics for potential applications in diverse fields. Research Highlights: Synthesis of La_1-xY_xFe_1-y Co_yO₃ (x = 0,0.10 & y = 0,0.03,0.05,0.07) nanoparticles by sol-gel method. Confirmation of orthorhombic structure with Pbnm space group from XRD, Rietveld and Raman analysis with a decrease in crystallite size from 48 to 12 nm. Disclosement of the presence of both Fe²⁺ and Fe³⁺ oxidation states and Co doping has a Co²⁺ oxidation state from XPS analysis. The bandgap tuning from 2.09 to 1.56 eV with an increase in Co²⁺ doping concentrations. Weak ferromagnetic behavior observed for all the NPs. Enhanced M_s, M_r, and H_c for the 7% Co²⁺ doped LFO. The 7% Co²⁺ doped LFO exhibited the highest dielectric constant, lowest tangent loss and highest conductivity. [ABSTRACT FROM AUTHOR]