Abstract
Sr-doped BaZrO3 nanoparticles with strontium content varying from 5 to 20 mol % were successfully synthesized by reverse micellar method at 900 degrees C for the first time. Systematic studies have been carried out to establish the structural and electrical properties of the as prepared nanoparticles. These nano particles were characterized using powder X-ray diffraction, transmission electron microscopy, BET surface area and dielectric measurements. X-ray diffraction analysis showed the formation of mono-phasic and highly crystalline nanoparticles which could be indexed in cubic BaZrO3 with contraction of lattice on strontium substitution. A monotonic shift of diffraction pattern towards higher angel confirms the formation of solid solutions of Ba1-xSrxZrO3 (0.05 <= x <= 0.20) which was corroborating well with lattice parameter studies. Transmission electron microscopic studies showed the formation of cubic, spherical and hexagonal nanoparticles with an average grain size of 40-65 nm. Energy dispersive X-ray spectroscopic studies confirmed the presence of dopant (Sr2+) in the BaZrO3 matrix and estimated chemical species corroborate well with the loaded composition. Specific surface area of the solid solution comes out to be in the range of 104-244 m(2) g(-1). Smallest particle of size 40 nm shows highest surface area 244 m(2) g(-1) for 20 mol% Sr-doped BaZrO3. Dielectric and impedance studies were also carried out as a function of frequency and temperature to explore the electrical properties of Sr-doped BaZrO3. The dielectric constant of Ba1-xSrxZrO3 (0.05 <= x <= 0.20) was found to be in the range of 13-25 for x = 0.05 to x = 0.20 with nearly similar dielectric loss of the order of 0.02. The conductance increases linearly with increase in frequency at room temperature, however the impedance has an inverse effect. (C) 2016 Elsevier B.V. All rights reserved.