Bismuth sodium titanate (Na0.5Bi0.5)TiO3 (NBT), is considered to be an excellent candidate for a key material of lead-free piezoelectric ceramics. In this study, we propose a stearic acid gel method for the preparation of nanocrystalline single phase NBT powder at relatively low treatment-temperature. Infrared (IR) spectroscopy, differential thermal analysis (DTA), thermogravimetric analysis (TG) and X-ray diffraction (XRD) were used to characterize the process of crystallization. The particle size and morphology of the calcined powders were examined by TEM. It shows that pure single phase NBT powders could be obtained at 700degreesC for 1 h, and the particle size is about 20 nm. With an increase in the calcination temperature, crystallite size increased. The powders were further pressed into disk and sintered at 1120degreesC for 2 h in air, and its density and microstructure were compared with traditionally prepared samples. (C) 2004 Elsevier B.V. All rights reserved.