Effect of Ball Milling Time on the Electrical and Piezoelectric Properties of Barium Titanate Ceramics

Barium Titanate (BaTiO3) is the first piezoelectric ceramic developed and most widely used though for few decades it has been replaced by better performed lead based materials like PZT, PLZT, etc. for piezoelectric applications. Recently, however, due to the environmental concern caused by lead based materials, researchers have been giving importance to this material and trying to improve its piezoelectric and electromechanical properties by performing various treatments. The present work is also an effort in this direction. Barium titanate (BaTiO3) powder was synthesized by solid state reaction of BaCO3 and TiO2 at 1050°C. X-ray diffraction analysis of the powder showed the single phase perovskite structure of BaTiO3. The powder was milled to produce nanocrystalline powders using a planetary ball mill. Different samples were prepared by varying the milling time from 1 to 30 hours, keeping the milling speed fixed at 250 rpm. All the milled powders were examined with TEM. With increasing milling time, the particle size first decreases and attains a minimum of 28.59 nm at 20 hours of milling time. However, further increase in milling time results in increase of the particle size. The electrical and piezoelectric properties of the ceramic samples formed by these nanocrystalline powders were studied.