Dielectric Relaxation in Zr‐Doped SrTiO3 Ceramics Sintered in N2 with Giant Permittivity and Low Dielectric Loss

Abstract

SrTiZrxO3 (x = 0, 0.002, 0.006, 0.01, and 0.014) ceramics with a weak temperature‐dependent giant permittivity (>104) and a very low dielectric loss (<0.01) were fabricated using the conventional solid‐state reaction method by sintering them in N2 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 SrTiO3 ceramics sintered in N2 were due to the existence of the giant defect dipoles generated by the fully ionized oxygen vacancies and Ti3+ ions, while the dielectric properties of SrTiZrxO3 (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.