Insights into the Structural, Electrical, Optical, and Dielectric Characteristics of Magnesium-Decorated Lanthanum Ferrite (La_0.75Mg_0.25FeO₃) by the Sol-Gel Method

Ferrites are ceramic products made mostly of iron oxide mixed with other metal oxides, like cobalt, nickel, zinc, or manganese. They are frequently employed as a fundamental substance in the electrical and electronics sectors because of their variable magnetic features, relatively low eddy-current distortion at elevated frequencies, and excellent electrical resistance. Lanthanum ferrite (LaFeO₃) has unique electrical, optical, and dielectric characteristics, along with high chemical stability, making it a viable perovskite-type material. Magnesium replacement can affect the crystalline structure, defect chemistry, and charge transfer pathways in order to vary its functionality. Mg replacement affects the structural, dielectric, electrical, and optical properties of La_2-xMg_xFeO₃ metallic materials, as previous studies have shown. The goal of the present research is to use the sol-gel technique to manufacture La_0.75Mg_0.25FeO₃ and examine its structural, electrical, optical, and dielectric properties for prospective applications in sensors, photocatalysis, electronic equipment, telecommunications, and shielding purposes. In order to comprehend the impact of the magnesium substitution process on the material's (La_0.75Mg_0.25FeO₃) structural characteristics and analyze its capability for anticipated purposes. The research intends to analyze crystalline phase development, crystallite dimensions, morphological characteristics, a standard optical spectrum width, electrical conductivity, and temperature-varying dielectric activity. The sol-gel method was used to create a set of magnesium-doped lanthanum ferrites La_0.75Mg_0.25FeO₃, which were then sintered at different temperatures that is 100°C, 300°C, 600°C, and 900 °C. In this study, XRD analysis confirmed the orthorhombic phase of La_0.75Mg_0.25FeO₃. The most noticeable peak (110) exhibits switching, and the average crystallite (D) size falls between 7.2 and 8.5 nm. With rising annealing temperatures, the X-ray density (ρ_x) progressively dropped from 7.27 to 6.88 g/cm², whereas the dislocation density (δ) steadily increased from 4.2 to 5.2×10¹⁵ lines/m² as the temperature rose. The large surface area (7.5 to 13.6 m²/g) suggests the use of supercapacitors and other energy storage devices. As annealing temperature rises, a decreasing pattern in the direct band gap (4.09 to 3.87 eV) and indirect transition (3.33 to 3.13 eV) has been noted. The low value of the refractive index (0.1 to 0.3) means these nano-materials can be utilized in making cladding of fiber optics and in solar cells to make an anti-reflection coating layer. SEM results showed the non-homogeneous morphology.