SYNTHESIS, STRUCTURAL AND ELECTRICAL PROPERTIES OF NANOCRYSTALLINE BARIUM TITANATE CERAMIC USING MECHANOCHEMICAL METHOD

Abstract

Barium Titanate (BaTiO3 or BT) powders were synthesized by a combination of solid state and mechanochemical method. The thermal decomposition, phase formation, microstructure and electrical behaviour were investigated by TG-DSC analysis, X-ray diffraction, FE-SEM measurements and impedance analyzer. The X-ray diffraction patterns show cubic symmetry without secondary phase. The lattice parameter a, c/a ratio and crystal size was found to be 4.0070 A, 1.0000 and 31.2nm. The FE-SEM results indicated dense microstructure with an average grain size of 144.53nm. the dielectric constant and loss of BT at room temperature were 1600 and 0.77 at 40Hz. The temperature dependence of dielectric permittivity shows that phase transition seems to be shifted towards lower room temperature Tc observed at 900C. The hysteresis loop was observed having a remanent polarization (Pr) and coercive field (Ec) of 0.27 Pr (uC/cm2) and 581.73 Ec (V/cm). The dielectric constants and relatively lower loss tangent values meet the current demand for device miniaturization in the electronics industry.