Exploring Fe-Doping Effects in K0.5Na0.5NbO3 (KNN) for Enhancing Electrical and Magnetic Properties

Abstract

K_0.5Na_0.5NbO₃-based ceramics owing to their outstanding properties have compelled the researcher’s attention as an innovative multifunctional material. The structural, dielectric, electrical and magnetic properties of polycrystalline perovskites of K_0.5Na_0.5Fe_xNb_1–xO₃ (x = 0.10, 0.15, 0.20) prepared by the conventional solid-state reaction method were investigated systematically. Interestingly, the XRD results revealed the successful formation of pure perovskite orthorhombic crystal structures without any secondary phases. Furthermore, Rietveld refinement analysis indicated a significant variation in the lattice parameters and unit cell volume. The microstructural analysis emphasized unique irregular rectangular grain morphologies with an average size of 0.6–0.9 μm, while EDX spectra affirmed compositional uniformity. Impedance spectroscopy provided a thorough analysis of the contributions from grain and grain boundary effects, elucidating the mechanisms behind the enhanced dielectric constant. The narrowing of the band gap is assessed using diffuse reflectance spectroscopy. The prepared samples can be utilized to improve the performance of materials used in optical data storage devices. The presence of Fe in various oxidation states, including Fe²⁺and Fe³⁺ was explored through X-ray photoelectron spectroscopy analysis. The magnetic measurements show that the prepared samples exhibit paramagnetic behavior. This research explores the ultimate functionalities of these samples paving the way for their application in advanced electronic and magnetic technologies.