Novel SrTiO₃-based ceramics with colossal permittivity, low dielectric loss, and high insulation resistivity via defect engineering

It is a great challenge to high colossal permittivity (CP, Ɛ_r) in polycrystal ceramics together with low dielectric loss (tanδ) and high insulation resistivity (ρ) due to the miniaturization of electrical devices. In this contribution, the defect dipoles [Ti⁴⁺•e−Ce_Sr^••−e•Ti⁴⁺] and [Ce_Sr^•−e•Ti⁴⁺] have been actively induced in the Sr_1-1.5xCe_xTiO₃ (SCT) systems by doping Ce ions with amphoteric nature to address this issue. The ultra-stable dielectric performance under the external stimulus, with Ɛ_r = 12,406 (with low variation of < ±10%) and tanδ <0.08, can be achieve in the x = 0.01 sample within the temperature range of 10–200 °C and at the frequencies ranging from 20 Hz to 1 MHz, accompanied by high insulation with ρ > 10¹⁰ Ω•cm with low degradation rate under harsh test conditions of 2–4.5 kV/cm. This work paves a path by multisite defect engineering to achieve high-performance CP ceramics.