Dielectric and microstructural properties of BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3 ceramics

摘要

BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3 ceramics were investigated regarding their dielectric and microstructure properties via conventional solid state reaction method. The phase pure samples were obtained when heated at 1400°C for overnight. The effect of Er~(3+) doped into BaTiO_3 on dielectric properties and microstructural properties was investigated for composition of BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3. The analysis was made by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Impedance Analyzer. The XRD patterns of BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3 are phase pure and identical with tetragonal perovskite structure with space group of P4mm. The lattice parameters and unit cell volume of BaTiO_3 increased by doping with Erbium as the crystallite size decreased. Measurements of dielectric properties were carried out as a function of temperature up to 200°C at different frequencies. Ba_(0.9925)Er_(0.0075)TiO_3 exhibit the high value of dielectric constant (ε=6179) at Curie temperature (T_C) of 120°C. SEM analysis of BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3 ceramics showed that the grain sizes of BaTiO_3 and Ba_(0.9925)Er_(0.0075)TiO_3 were ranged from 3.3μm-7.8μm and 2.2μm-4.7μm respectively.