Hydrothermal Synthesis and Dielectric Properties of Ba1-xSrxTiO3 Nanoparticles with Enhanced Uniformity

Abstract

A facile hydrothermal method was used to obtain uniform Ba1-xSrxTiO3 (BST) nanopowders. The uniformity of the synthesized powders varied with the addition of ethanol and diethylene glycol (DEG). The formation of amorphous colloidal precipitates occurred during the addition of ammonia solution. The gel-like colloids promotes faster and more uniform reaction. They cause enhancement in the uniformity of the synthesized BST particles. Morphological changes such as size and uniformity, were observed using scanning electron microscopy. Changes in the lattice parameter and compositional changes of the synthesized BST powders in response to the strontium (Sr) molar concentration were characterized using X-ray Fluorescence and X-ray diffraction. The synthesized BST powders possessed the designed stoichiometric proportions. Two parallel conductive plates were aligned and fixed using commercial cellophane tape to have small gap to contain liquids. These were designed to measure the dielectric permittivity of the synthesized powder slurries having different volume fractions. The permittivity of the powder was obtained under the assumption of 100 vol% of powder by calculating the extrapolation based on the measured values using the generalized dielectric mixture rule.