Abstract
A sol-gel preparation of BaTiO 3 has been developed by the addition of a chelating agent CH 3 COCH 2 COCH 3 to a Ba(CH 3 COO) 2 and Ti(O-iPr) 4 to form the precursors, initially, followed by the addition of a nonionic surfactant nonylphenoxypolyethoxyethanol (NPE). The NPE adsorbed on the precursors constitutes a steric barrier against flocculation to stabilize the precursors. The added NPE does not alter the tetragonal phase of the BaTiO 3 . The BaTiO 3 prepared from precursor solution containing 4% NPE consists of grains with ca. 1.1 μm in size. The corresponding dielectric constants are 3500 at 1 kHz and 2000 at 1 MHz, respectively. The improved dielectric properties are ascribed to the increased bonding and steric hindrance induced by the adsorbed NPE. The results illustrate the merits of altering the chemistry and processing environment of sol-gel prepared precursors to control the dielectric property of the BaTiO 3 .