Dielectric properties of spark plasma sintered BaTi₂O ₅ ceramics prepared through sol-gel process

Barium dititanate (BaTi₂O₅) ceramics with high density and phase purity were fabricated by spark plasma sintering (SPS) from the sol-gel derived powders. The fine grained ceramics exhibited a diffuse phase transition which is qualitatively the same as the conventional defects induced relaxor behavior but different in high transition temperature and weak diffuseness. Furthermore the dielectric constant of the present BaTi ₂O₅ ceramics showed an abnormal enhancement under the dc bias. The tunability can reach 58%. This can be explained by the favor of b-axis during the cooling process with the help of the dc bias.