Colossal Permittivity Characteristics and Origin of (Sr, Sb) Co-Doped TiO₂ Ceramics

Abstract

With the continuous development of electronic technology, the application of dielectric materials is also becoming more and more abstractive. It is also a great challenge to find a new type of colossal permittivity material with high dielectric permittivity, lower dielectric loss and excellent temperature and frequency stability. In this work, the (Sr1/3Sb2/3) x Ti1−x O2 (SSTO) colossal permittivity ceramics for x = 0, 0.5%, 1.0%, 1.5%, 2.0%, 4.0% were prepared by conventional solid state reaction method. The crystal structure, microstructure, dielectric properties, varistor properties were analyzed, and the formation mechanism of colossal dielectric was revealed. When the doping amount is 2%, SSTO has the optimal dielectric performance with dielectric constant of approximately 2.2 × 104, dielectric loss of about 0.03 at 1 kHz. X-ray photoelectron spectroscopy (XPS) and Impedance spectra (IS) results showed that defect clusters and interface polarization are the main reasons for the improvement of dielectric properties of (Sr, Sb) co-doped TiO2 ceramics. Therefore, this work is of great significance for the development and application of TiO2-based new colossal dielectric materials.

Dielectric Performance of DC Electric Field-Assisted Flash Sintered (Sr, Sb) co-doped TiO2 Ceramics

“…The permittivity has good stability over a wide frequency range (10 2 ∼ 10 7 Hz), all above 10 3 , and the results were similar to those obtained by conventional sintering. [38][39][40] As the doping concentration increases, the dielectric constant increases and then decreases, and the amplitude is large. Meanwhile, the dielectric loss shows the same pattern with the appearance of peaks.…”

“…The presence of Sb 3+ may be caused by the reduction of Sb 5+ at high temperatures. 40,46 The reaction involved in this process is shown in the following formulas: To further analyze the origin of the dielectric permittivity of codoped TiO 2 ceramics, impedance tests were performed on the flashsintered ceramic samples at room temperature, as shown in Fig. 11.…”