Good thermal stability, giant permittivity, and low dielectric loss for X9R‐type (Ag_1/4Nb_3/4)_0.005Ti_0.995O₂ ceramics

Abstract

With the intense demand of the developing microelectronics market, the study of giant permittivity dielectric materials is being promoted. However, it is difficult to obtain suitable dielectric materials for such applications, especially due to high dielectric loss at low frequencies. In this work, Ag+Nb codoped TiO2 ceramics were designed and fabricated in a conventional solid reaction by sintering at 1290‐1340°C for 5‐10 hours. The issue of how the microstructure and dielectric properties of (Ag1/4Nb3/4)0.005Ti0.995O2 ceramics are affected by the sintering conditions was discussed. By optimizing sintering conditions, a dense microstructure, a high dielectric constant (εr ≈ 9410), and a low dielectric loss (tanδ ≈ 0.037) at 1 kHz were achieved. Most importantly, the temperature coefficient value of εr at different frequencies remained stable between −14.3% and 13.7% within the temperature range from −190 to 200°C, which has potential applications in X9R capacitor.

DFT calculations and giant dielectric responses in (Ni1/3Nb2/3)xTi1−xO2

“…This outcome aligns with observations in other acceptor/donor co-doped TiO 2 materials. 1,40,41 The substitution of co-dopant Ni 2+ and Nb 5+ ions at the Ti 4+ sites leads to a signicant expansion of the lattice parameters. This expansion provides crucial evidence supporting the incorporation of Ni 2+ and Nb 5+ ions at the Ti 4+ sites without the emergence of secondary phases.…”

Colossal Permittivity Materials as Superior Dielectrics for Diverse Applications

“…was synthesized as a CP material. [195] Based on the Hume-othery rule, the ionic radii difference between doped and host ions should be smaller than 15% to form substitutional solid solutions. However, most acceptor ions have large radii, typically beyond this limit.…”

Structural and Dielectric Properties of Titania Co-Doped with Yttrium and Niobium: Experimental Evidence and DFT Study

“…Pure TiO 2 exhibits a moderate electric permittivity (ε ′ ~200 at room temperature [8]). In the last decade, TiO 2 co-doped with acceptor and donor cations has emerged as a new family of dielectric ceramics with promising properties such as colossal permittivity and low dissipation factor [9][10][11][12][13]. The combination of the pure titanium oxide properties with those acquired by co-doping opens a promising route to obtain high-performance dielectric ceramics for applications in microelectronics and energy storage devices.…”