Dielectric Relaxation in Zr ‐Doped SrTiO 3 Ceramics Sintered in N 2 with Giant Permittivity and Low Dielectric Loss

SrTiZr x O 3 ( x = 0, 0.002, 0.006, 0.01, and 0.014) ceramics with a weak temperature‐dependent giant permittivity (>10 4 ) and a very low dielectric loss (<0.01) were fabricated using the conventional solid‐state reaction method by sintering them in N 2 at 1500°C. With increasing Zr content, the permittivity decreased from approximately 48 000 to 18 000 and the dielectric loss decreased from approximately 0.005 to 0.003. According to the XRD , XPS , and ac conductivity analysis, the dielectric properties of pure SrTiO 3 ceramics sintered in N 2 were due to the existence of the giant defect dipoles generated by the fully ionized oxygen vacancies and Ti 3+ ions, while the dielectric properties of SrTiZr x O 3 ( x > 0) ceramics were also influenced by the defect dipoles ( ). The giant permittivity and low dielectric loss phenomenon could be explained by giant defect dipoles related to oxygen vacancies.