Investigation of structural, topological, and electrical properties of scheelite strontium molybdate for electronic devices

Abstract

This article describes the synthesis (solid-state reaction) and characterizations of a scheelite strontium molybdate. The consistency of lattice parameters by N-TREOR09 and the Le-Bail Rietveld refinement method supports the tetragonal crystal system. The spectrum of the pair distribution function (PDF) depicts the orientations of atoms within a tetragonal symmetry. The Williamson-Hall plot examines the average crystallite size (86 nm) and micro-lattice strain (0.00091). The scanning electron microscopic image, energy dispersive X-ray (EDX) spectra, and elemental mapping confirm the uniform and isotropic characteristics of the synthesized material, purity and compactness, and topographic roughness according to ISO25178 standards. The investigation of dielectric, impedance, and conductivity spectra confirms the presence of Maxwell-Wagner dielectric dispersion, relaxation, and influential transport phenomena across a broad spectrum of experimental frequencies (ranging from 1 kHz to 1 MHz) and temperatures (from 25 °C to 500 °C). The observed temperature-dependent resistance characteristics validate that the prepared material is well-suited for applications involving PTC thermistors, sensors, and other related devices. The scaling properties of the modulus data provide evidence for a non-Debye relaxation mechanism. The values of the varistor constant, β1, β2, and β3, which are 1.414, 2.362, and 9.654, respectively, indicate the existence of Ohmic conduction, trap-limited space charge limited conduction (SCLC), and trap-filled SCLC mechanisms suitable for electronic devices.