Role of Strontium in Structural and Dielectric characterstics of Barium Titanate

Abstract

Ba₀.₇₅Sr₀.₂₅TiO₃ (BST) compound was synthesized through the conventional solid-state reaction methodology, aimed at investigating its structural, microstructural, and dielectric characteristics. The structural characterization was executed employing X-ray diffraction (XRD), and the resultant diffraction patterns were refined utilizing the Rietveld method, which substantiated the establishment of a single-phase perovskite configuration exhibiting tetragonal symmetry and belonging to the P4mm space group. The refined lattice parameters revealed subtle distortions correlating with the substitution of Sr at the A-site of the BaTiO₃ lattice. The tetragonality factor also exhibited slight variations, indicating the influence of Sr incorporation on the symmetry of the crystal structure.Using Scanning Electron Microscopy (SEM), we demonstrated the existence of well-defined grains noted for substantial grain development and a solid microstructure, which are both favorable for boosting dielectric and ferroelectric effectiveness. The substitution of Sr for Ba was observed to exert a profound impact on the electronic environment, consequently modifying the characteristics of the Ti–O bonds and altering the local polar distortions within the lattice framework. These alterations contributed to the stabilization of ferroelectric ordering and enhanced the dielectric response of the material.Dielectric measurements demonstrated an elevation in the dielectric constant concomitant with Sr doping, which can be ascribed to augmented polarizability and optimized grain connectivity. Furthermore, the analysis of ferroelectric hysteresis (P–E) loops revealed increased remnant polarization and coercive field, signifying improved ferroelectric behavior in comparison to undoped BaTiO₃. The introduction of Sr ions engenders local lattice strain and modulates the band structure, thereby playing a pivotal role in fine-tuning the electrical and ferroelectric properties of BST.In summary, the study elucidates that Sr doping in BaTiO₃ effectively modulates both the structural and dielectric attributes, rendering Ba₀.₇₅Sr₀.₂₅TiO₃ a compelling candidate for electronic and capacitor-based applications that necessitate materials with superior dielectric and ferroelectric performance.