Structural, dielectric, electrical, and leakage current properties of SrWO₄ for electronic devices

Using a standard ceramic technology (i.e., a solid-state reaction method), a strontium tungsten ceramic compound of a chemical formula SrWO₄ (SWO) was fabricated. The compound was formed in tetragonal crystal symmetry (space group I41/a), as demonstrated by analyzing the room-temperature X-ray diffraction data. The calculated lattice parameters are; a = 5.4168 ± 0.0003 Å, b = 5.4168 ± 0.0003 Å, and c = 11.9510 ± 0.0016 Å with cell volume = 350.69 (Å)³. The grain and crystallite sizes, determined by diffraction (X-ray and electron) data, are 8.43 μm and 31 nm, respectively. Analysis of dielectric data has provided a high dielectric constant and a low tangent loss at room temperature, suggesting its capacitive and resistive characteristics. The existence of grain and grain boundary effects, as well as the negative temperature coefficient of resistance (NTCR) behavior, are confirmed by the impedance spectra analysis. The modulus study shows that relaxation is non-exponential and depends on dependent temperature conductivity. The leakage current characteristics indicate that the material exhibits Ohmic and space charge limited conduction (SCLC) conduction mechanisms at room temperature on varying electric field. The material is identified for the NTC-thermistor device by its essential characteristics.