Colossal permittivity of (Tm+Nb) co-doped rutile-TiO2 ceramics with ultralow dielectric loss and excellent thermal stability

Abstract

(Tm0.5Nb0.5)xTi1−xO2 (x = 0, 0.01, 0.02, 0.04 and 0.06) (TNTO) ceramics were prepared by solid-state reaction method. The effect of (Tm+Nb) co-doping concentration on the phase, microstructure and dielectric properties of the fabricated ceramics were investigated. A ultralow dielectric loss (0.006, at 1 kHz) and colossal permittivity (CP) (2.17 ×104, at 1 kHz) were obtained in the prepared TNTO ceramics (x = 0.01). The dielectric properties of the (Tm0.5Nb0.5)0.01Ti0.99O2 ceramics show excellent temperature- and frequency-stability in the range of − 150–260 °C (Δε′ (T)/ε′30< ± 15%, at 1 kHz) and 20–106 Hz. It was found that, the dielectric properties of (Tm+Nb) co-doped TiO2 ceramics have three significant temperature-dependent relaxations caused by electron-pinned defect-dipoles (EPDD) effect, internal barrier layer capacitance (IBLC) effect and electrode effect, respectively. The reported (Tm+Nb) co-doped TiO2 ceramics with ultralow dielectric loss and excellent thermal stability could be considered as one of the most promising candidates for applications in microelectronics.