Novel defect clusters from density functional theory calculations for colossal dielectric response in In 3+ and F − co‐doped TiO 2 ceramics
At a Glance
Section titled “At a Glance”| Metadata | Details |
|---|---|
| Publication Date | 2025-06-05 |
| Journal | Journal of the American Ceramic Society |
| Authors | Ying Xue, Zhuo Wang, Caidan Hou, Xin Li, Zixiong Sun |
| Institutions | Shaanxi University of Science and Technology |
Abstract
Section titled “Abstract”Abstract In TiO 2 colossal dielectric ceramics co‐doped with In 3+ and Nb 5+ , the electron‐pinned defect‐dipoles effect is strongly influenced by the adjacent and overlapping interaction between diamond ( (A = Ti 4+ /In 3+ /Ti 3+ )) and triangle () defect clusters. Although acceptor doping introduces oxygen vacancies () that facilitate the formation of triangular () defect clusters, this doping inevitably results in the presence of additional diamond ( (A = In 3+ )) defect clusters. Unfortunately, this structure complexity hinders a clear understanding of the intrinsic relationship between the colossal dielectric properties and low‐temperature dielectric relaxation associated with individual defect clusters. Therefore, creating novel defect clusters to achieve high electron localization is crucial for the advanced TiO 2 ‐based ceramics. Herein, a colossal dielectric constant of up to 3.4 × 10 4 and a low dielectric loss of 0.044 are observed at 1 kHz and room temperature for the first time in cation-anion (In 3+ and F − ) co‐doped TiO 2 ceramics. Meanwhile, the materials exhibit excellent frequency stability and meet the temperature requirements defined by the X9R standard. Dielectric relaxation associated with electrons in the low‐temperature range of 2-30 K is attributed to the generation of novel diamond defect clusters (). Combined with density functional theory calculations, the notable electronegativity of F − promotes electron localization without relying on ‐related defect clusters formations. Overall, the study presents a novel strategy for designing next‐generation colossal dielectric ceramics.