Interface effects and defect clusters inducing thermal stability and giant dielectric response in (Ta plus Y)-co-doped TiO2 ceramics

High-performance giant dielectric ceramic materials are essential for the advancement of electronic devices. In this work, (Y0.5Ta0.5)(x)Ti1-xO2 (x = 0, 0.01, 0.02, 0.04, 0.06, labeled as YTTO-0, YTTO-0.01, YTTO-0.02, YTTO-0.04, and YTTO-0.06, respectively) ceramics with giant dielectric constant (GDC), low dielectric loss (tan delta), and good temperature and frequency stability were prepared by solid-state reaction method, and the microstructure and dielectric properties were investigated. Notably, the sample with x = 0.01 shows a GDC (epsilon = 2.97 x 10(4)) and low tan delta (0.022). In addition, the dielectric constant at high frequencies (> 10(6) Hz) is related to the electron-pinned defect-dipole effect. On the contrary, the dielectric constant at low and medium frequencies (< 10(6) Hz) is related to the internal barrier layer capacitance effect and the electrode effect. Moreover, the polarization strength of the interface gradually increases with the increase of doping amount. This investigation could increase our understanding models of multiple dielectric relaxations and inhomogeneous composition in co-doped rutile TiO2.

Automated summary

High-performance giant dielectric ceramic materials are prepared in this study, and the sample with x = 0.01 shows the best dielectric performance. The dielectric constant varies with frequency, being related to the electron-pinned defect-dipole effect at high frequencies and the internal barrier layer capacitance effect and electrode effect at low and medium frequencies.