Effect of Sr2+ doping on structural, dielectric, electrical, and optical properties of BaTiO3 ceramics

Abstract

The proposed article provides insights into the impacts of Sr substitution on the structural, electrical, dielectric, and optical properties of barium titanate (BT). Fabrication of the series Ba_1-xSr_xTiO₃ (x = 0.03, 0.05, 0.07) (BST) has been accomplished via solid-state reaction route with the additive advantage of being eco-friendly. X-ray diffraction (XRD) supported by the Rietveld refinement elucidated phase purity, single phase, and crystalline behavior of synthesized ceramics. Structural studies were lightened by the Fourier transform infrared spectroscopy (FTIR) whose analysis demonstrated in the range of wavenumber 400 to 4000 cm⁻¹. It validated BaTiO₃ by marking the presence of a prominent peak of Ti–O’s ‘stretching vibration’ within TiO₆ octahedron. Here, the blue shift that occurred was attributed to the Sr substitution. The scanning electron microscope (SEM) along with energy-dispersive X-ray spectroscopy (EDS) provided a glance on the morphological and compositional analysis. Both tangent loss (tanδ) and dielectric constant exhibited dispersion at low frequency. The variation of DC electrical conductivity with temperature signified the semiconducting behavior of the synthesized material. UV–vis spectroscopy analysis was performed in DRS mode in the wavelength range of 200–800 nm. Tauc’s plot and absorbance spectra indicated that the optical bandgap increases upon adding Sr²⁺ ions compared to pristine BT. For structural purity, the Raman Spectroscopy has been performed in the wavenumber range of 200–1000 cm⁻¹. These findings contribute that BST is a promising material for a variety of applications mainly in the field of optoelectronic devices operating in the visible range.