Investigation of Barium Strontium Titanate (Ba0.95Sr0.05TiO3) synthesized via conventional solid-state reaction and co-precipitation route with diverse sintering temperatures

Abstract

Barium Strontium Titanate (BST) includes ferroelectric material extensively studied due to its fascinating properties. Ba0.95Sr0.05TiO3 pellets have been prepared using two techniques of co-precipitation and solid-state reaction sintered at diverse temperatures of 900, 1000 ℃, 1100 ℃, and 1200 ℃ for 4 h. This study aimed to compare the two techniques based on the structural, microstructure, and electrical properties varied by sintering temperatures. The sample testing was performed using X-ray Diffraction (XRD), revealing that the coprecipitation needs a higher sintering temperature to obtain pure BST (1200 °C) compared to the solid-state route (1000 °C). The lattices and crystal sizes of both routes were not significantly different. The yields of the Scanning Electron Microscopy (SEM) characterization showed that both methods showed reduced porosity and larger grain size with increasing sintering temperature, but the co-precipitation produced higher density and less porosity than that of the solid-state technique. The hysteresis pattern was measured using Sawyer Tower, which resulted that the hysteresis loops of the precipitation were greater than the solid-state route in which the higher sintering temperature could broaden the loops. The effect of sintering temperature causes the dielectric constant to increase in both methods. Overall, the dielectric constant of all samples with the coprecipitation route is greater than the solid-state method. The highest dielectric constants for both routes are 589 (co-precipitation) and 216 (solid-state) at a frequency of 40 kHz and sintering temperature of 1200 °C. Thus, based on this study, co-precipitation is preferred to synthesize BST.