In this paper, we report the enhancement of the dielectric constant of barium titanate (BTO) through partial substitution of strontium to barium and crystallite size reduction through a high power ultrasonic treatment. The sample under investigation is Ba1-xSrxTiO3 or BST with x = 0 and 0.3 compositions prepared through mechanical alloying of SrCO3, BaCO3 and TiO2 precursors as the feedstock. All mechanically alloyed samples were crystalline powders with a single phase as confirmed by an x-ray diffractometer (XRD). The mechanically alloyed materials were consisted of multi-crystallite particles as confirmed both by XRD data analysis and particle size evaluation. Subject to an additional ultrasonic treatment, the multi-crystallite particles were fragmented toward mono-crystallite particles with the mean crystallite size about 52 nm after 12 hours irradiation. Even a smaller mean crystallite size (18 nm) with a narrower crystallites distribution then that of BTO was obtained in Ba1-xSrxTiO3 with x = 0.3. Such a narrow crystallite size distribution with a small mean crystallite size has superior dielectric constant over those of BTO and doped BTO with a large mean crystallite size. The highest dielectric constant of 3000 was obtained at a frequency of 273 Hz in doped BTO after 12 hours ultrasonic irradiation. The value is 12 times higher than those of BTO and doped BTO with a large crystallite size.
|Journal||IOP Conference Series: Earth and Environmental Science|
|Publication status||Published - 25 Jan 2018|
|Event||2nd International Tropical Renewable Energy Conference, i-TREC 2017 - Bali, Indonesia|
Duration: 3 Oct 2017 → 4 Oct 2017