Low Temperature Synthesis of Barium Titanate Powder by a Modified Sol-Gel Method

Abstract

Barium titanate (BT) is one of the most important lead-free ferroelectric materials with perovskite crystal structure and high dielectric constant. Among synthesis techniques of BT, sol-gel processing has attracted considerable interest due to the control of composition, surface morphology engineering, low temperature processing, and low equipment cost. In this research, nanocrystalline BT powders were prepared by a modified sol-gel technique. Acetic acid and water were used as solvents. The samples were heat treated at various temperatures, times, and rates for investigating the effect of heat treatment parameters on formation of single perovskite crystalline phase. According to the results of X-ray diffraction analysis, highly pure BT powder with minimum secondary phases (Magneli) was obtained after calcination at 650 °C for 1 h with the rate of 10 °C/min. The grain size and morphology of BT powders were obtained by field emission scanning electron microscopy which indicated the size of about 60 nm.