ZHU Guibing ^1,2, WANG Chunchang ² , TONG Lei ²

(1. Nanjing Vocational College of Information Technology, Nanjing, 210046, Jiangsu, China; 2. Laboratory of Dielectric Functional Materials, Anhui University, Hefei 213001, Anhui, China)

Abstract: 10mol% Gd ion-doped CeO₂ (GDC10) nano-ceramics were prepared from powder made with sol-gel method. Phase composition, morphology, grain size and specific surface area of the calcined powder were characterized. Dielectric parameters of the ceramic samples were measured by using a series of testing methods. The dielectric properties and the mechanism of dielectric relaxation of the samples over the temperature range of 300-900 K and the frequency range of 1´10²-1´10⁶ Hz were studied. It was found that Gd ions can be well doped into the lattice of CeO₂, resulting in a large number of oxygen vacancies. A parabolic increase in dielectric constant of the GDC10 sample was observed in the middle and low temperature regions. It is the humidity sensitive behavior that restrained the formation of dielectric relaxation and result in the increase in dielectric constant to a considerable degree.
Key words: GDC10 ceramics; relaxation; dielectric; sol-gel method; doped cerium oxide