Electrical, magnetic, and Raman spectroscopic studies on Bi-modified YIG ceramics

This study delves into an exploration of both electrical and magnetic characteristics exhibited by the Y₃Fe₅O₁₂ (YIG) and Bi-modified YIG (Bi_0.2Y_2.8Fe₅O₁₂; BYIG) materials, which were prepared through the process of solid-state route. The crystal structures of all the synthesized materials were confirmed, using X-ray diffraction analysis which confirms the formation of a single-phase cubic structure. Energy-dispersive X-ray spectroscopy confirmed that the sample does not contain any impurities other than the constituent elements. The crystallite SEM images of Bi-modified YIG (BYIG) have shown bigger granular grains with uniform distribution. X-ray photoelectron spectroscopy measurements were also performed to understand the origin of oxygen vacancies and their chemical surrounding of Fe²⁺ and Fe³⁺ ion concentration. Detailed impedance spectroscopic studies were made in the frequency range of 100 Hz to 1 M Hz at different temperatures (RT-625 K). The broad dielectric peak observed near 473 K confirms the diffused phased transition (DPT) of the sample. From magnetic hysteresis studies, all samples have shown the saturation magnetization of 20 emu/g at room temperature. A combined electrical and magnetic study reveals the inheriting magneto-dielectric characteristics of BYIG. The results were corroborated by the Raman spectroscopic plots.