Abstract:
This study explores the structural, dielectric, impedance, and optical characteristics of the perovskite compound Sr(Mn0.45Fe0.05)Nb0.5O3. The compound was prepared by the solid-state mixed-oxide method. X-ray diffraction analysis confirmed a single-phase tetragonal crystal structure (a=5.6425 & Aring;, b=5.6425 & Aring;, c=7.9468 & Aring;, space group I4/mcm). Morphological analysis revealed an almost uniform grain distribution with minimal spacing. The Maxwell-Wagner phenomenon was observed in the frequency-dependent dielectric properties by considering various polarization mechanisms. A dielectric anomaly indicating a ferroelectric to paraelectric phase transition was observed around 260 degrees C during the temperature-dependent dielectric study. Impedance analysis demonstrated the NTCR behavior of the material. According to Jonscher's power law, conduction is governed by nonoverlapping small polaron tunneling, explaining the relationship between conductivity with frequency. The activation energies for relaxation and conduction suggest electron hopping. Estimated band gap of 1.91eV is applicable for optoelectronic devices. The temperature-dependent resistance analysis indicates potential applications in N-type thermistors. The M-H hysteresis loop's nonlinearity curve suggests weak ferromagnetism at low temperatures.
