Abstract: Nanocrystalline BaTiO3 is prepared using a stearic acid gel method. The synthesis process, crystalline structure and grain sizes of nanocrystal are investigated by differential thermal analysis, thermogravimetric analysis, infrared spectra and X-ray powder diffraction. The experimental results of dielectric properties of nanocrystal indicate that the dielectric constant ε of nanocrystal is much larger than that of bulk materials. With reducing of grain size, the ε of nanocrystalline material increases first, then it falls to smaller value. With the increment of relative humidity, the ε grows up. The relationship between ε and humidity becomes linear with high enough humidity.

Key words: Dielectric properties, BaTiO₃, Nanocrystal, Sol-gel