ABSTRACT TiO 2 ‐based colossal permittivity ceramics with high dielectric constant and low loss have become one of the key candidates for high‐capacity high‐end capacitors. This study investigates the influence of oxygen vacancy concentration on the dielectric properties of TiO 2 ‐based ceramics by adjusting the acceptor‐to‐donor ratio, and finds that the (In x Nb 1− x ) 0.005 Ti 0.995 O 2 (INTO) sample with x = 1/3 exhibits ultra‐low dielectric loss (tan δ) of 0.013 as well as high dielectric constant ( ε r ) of 1.7 × 10 4 (1 kHz). The results obtained from dielectric property measurements, relaxation behavior analysis, and X‐ray photoelectron spectroscopy indicate that the high dielectric constant and low dielectric loss originate from the synergistic effect between oxygen vacancy‐related defect clusters and electron‐pinned defect dipoles. This work not only provides a new strategy for achieving colossal permittivity and ultra‐low loss simultaneously via oxygen vacancy tailoring in TiO 2 ‐based ceramics and related materials, but also develops promising candidates for high‐capacitance ceramic capacitors.
Zhang et al. (Mon,) studied this question.