Structure and Electrical Characteristics of BaTiO_3 and Ba_(0.99）Er_(0.01)TiO_3 Ceramics

摘要

Conventional solid state reaction method was used to prepare BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 ceramics. Influence of Er~(3+) ion incorporation on their structural, microstructural and electrical properties was studied. The phase pure samples were obtained when heated at 1400℃ for overnight. The tetragonal perovskite phase of BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 was confirmed by using X-ray Diffraction (XRD) analysis which is in agreement with results obtained from Rietveld refinement analysis. The lattice parameters and unit cell volume of BaTiO_3 increased when doped with Erbium. Microstructural analysis of BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 ceramics showed that the grain sizes of BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 significantly decreased. The dielectric properties of BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 were investigated as a function of temperature and frequency. It revealed that the Curie temperature (Tc) increased by doping Er content from 110℃ to 120℃. Ba_(0.99)Er_(0.01)TiO_3 exhibited the high value of dielectric constant (ε=5929) at T_C of 120℃. The capacitance-voltage characteristic revealed that the voltage breakdown for both BaTiO_3 and Ba_(0.99)Er_(0.01)TiO_3 exceeded 30 V.