Phase formation and dielectric properties of Ba0.5Sr0.5TiO3 by slow injection sol-gel technique

A simple sol-gel process incorporating slow precursor injection technique was employed to synthesize homogeneous Ba0.5Sr0.5TiO3 nano powders. The Ba0.5Sr0.5TiO3 samples were subjected to calcination temperatures from 600 to 1,100 degrees C and sintering temperatures from 1,250 to 1,350 degrees C for the study of phase formation, crystallite size, particle distribution, and dielectric properties. Single phase Ba0.5Sr0.5TiO3 with a cubic perovskite structure was successfully synthesized after calcination at 800 degrees C. The average size of the nano particles is 42 nm with a narrow size distribution, and a standard deviation of 10%. The highest values recorded within the investigated range for dielectric constant, and dielectric loss measured at 1 kHz are 1,164 and 0.063, respectively, for Ba0.5Sr0.5TiO3 pellets calcined at 800 degrees C and sintered at 1,350 degrees C. Leakage current density measured at 5 V for the Ba0.5Sr0.5TiO3 pellet was found to be 49.4 pA/cm(2).