Ultrahigh insulation resistivity potential under colossal permittivity SrTiO3 based ceramics via controlling oxygen backfill

Abstract

Effects of annealing atmosphere on the dielectric properties of Sr1-xErxTiO3 ceramics (x = 0–0.014) were systematically investigated in this paper. In x = 0.012 ceramic samples annealed in air, the stable insulation resistivity of over 109 Ω • cm (DC 0–150 V), the CP (16,635 @ 1 kHz, 16,822 @ 1 MHz), and the ultralow dielectric loss (0.006 @ 1 kHz, 0.02 @ 1 MHz) are achieved. Through a thorough examination of dielectric responses, X-ray photoelectron spectroscopy (XPS), UV–visible absorption spectrum, and complex impedance data, it is demonstrated that the defect dipoles [TiTi′−VO··−TiTi′], [ErSr·−TiTi′],[2ErTi′−VO··], [TiTi′−VO·], [ErTi′−VO·] and [ErSr·−ErTi′] form in Sr1-xErxTiO3 (when x = 0.012) ceramic annealed under flowing air. We innovatively used variable temperature in situ resistance monitoring equipment to simulate the industrial environment, the insulating properties and the microscopic mechanism of oxygen vacancy diffusion of ceramics were investigated under different voltages and temperatures, which is of great significance to achieve more desirable colossal permittivity, ultra-low dielectric loss and insulation resistivity performance for real applications.