Effect of Sr-doping on structural, morphological and dielectric properties of BaTi0.93Sn0.07O3 ferroelectric ceramics

Abstract

In this report, we studied the Ba1-xSrxTi0.93Sn0.07O3 (x = 0.00, 0.10, 0.20, and 0.30) Perovskite ceramics produced by solid-state reaction (SSR) method and investigated their structural, morphological and dielectric properties by XRD, SEM, and LCR meter respectively. The Rietveld refinement of the XRD pattern confirms the samples crystallize in the Perovskite structure and transform from tetragonal for x = 0.0 to the co-existence of both cubic (Pm-3m) and tetragonal (P4mm) phases near room temperature for x ≥ 0.10. The Williamson-Hall (W–H) method has been used to determine the crystallite size and microstrains from the XRD peaks analysis, which showed the crystallite size value decreases with increased doping with Sr. The surface morphology shows the formation of ceramic grains with well-defined grain boundaries, as well as a decrease in grain size with an increase in the doping ratio. Moreover, the elemental ratio of doped ions was confirmed by EDS. The dielectric properties (έ, and tanδ) were studied as a function of temperature (20–150 °C) and a frequency (20 kHz - 3 MHz). The values of the dielectric constant έ decrease with the higher the frequency used. A diffuse phase transition was observed when doped with Sr. Where doping with Sr causes outstanding stability of έ values, which is evident by the flattening the dielectric constant curve, addition to increasing the dielectric constant values over range studied temperatures.

Keywords

• Materials science
• Ferroelectrics
• Ceramics
• Crystal structure
• Dielectric properties