Investigating the distinctive structural, dielectric, magnetic, and optical properties of lead-free ceramic: Sr(Mn0.40Fe0.10)Nb0.5O3 to drive advancements in device technology

This study presents the synthesis via solid-state reaction and a comprehensive characterization of a novel, environmental friendly perovskite compound, Sr(Mn0.40Fe0.10)Nb0.5O3. X-ray diffraction (XRD) show a tetragonal symmetry (a = 5.6421 Å, b = 5.6421 Å, c = 7.8984 Å, space group I 4/mcm). The lattice strain and average crystallite size were determined to be 0.0003 and 60 nm, respectively. The grain distribution and elemental composition of the compound were examined through scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) respectively. Additionally, Raman study was illustrated to investigate the vibrational modes present in the compound. UV–visible spectroscopy yielded a bandgap energy (Eg) of 1.66 eV, suitable for optoelectronic device applications. The contribution of Fe3+ ions was found to enhance the dielectric constant. The temperature dependence of the dielectric constant can be attributed to space-charge polarization mechanism. Furthermore, the conductivity behaviour adheres to Jonscher’s power law. An impedance measurement signifies the potential of the material as a negative temperature coefficient (NTC) thermistor device. The analysis of the ZFC and FC magnetization curves measured at 5000 Oe within the temperature range of 300–10 K highlights the considerable influence of annealing temperature on magnetic anisotropy and inter-particle interactions.