Abstract
This study examined the effects of Ni(2+) substitution on the structural, microstructural, optical, and dielectric properties of Sr(2)(Mn(1-x) Ni (x) )WO(6) (0.00 ≤ x ≤ 0.40) double perovskites using a normal processing approach. Each sample's monoclinic structure and space group (P21/n) were verified using the X-ray diffractometry (XRD) technique. Successful ionic substitution was indicated by the XRD results, which showed a systematic drop in lattice parameters and unit cell volume with increasing Ni(2+) content. Along with a rise in the lattice strain and dislocation density, the average crystallite size shrank from 58 nm (x = 0.00) to 47 nm (x = 0.40), indicating increased structural deformation. Images from scanning electron microscopy (SEM) revealed dense, crystalline microstructures with average grain sizes that gradually decreased as the Ni(2+) content increased. This might be explained by the difference in the ionic radii between the host and substitution elements. With Ni(2+) concentrations, the band gap energy increased from 3.10 eV to 3.51 eV, as shown by the ultraviolet visible (UV-vis) spectrometry results. The photon excitation energy varied between 2.65 eV and 1.76 eV with Ni(2+) concentrations, according to photoluminescence (PL) studies. Dielectric properties, such as the dielectric constant and tangent loss, have been shown to vary with frequency. Generally speaking, the structure and characteristics of Sr(2)MnWO(6) are successfully modified by the addition of Ni(2+), resulting in an appropriate band gap, low dielectric loss, and high dielectric permittivity.