Effects of Dy doping amount and sintering process on the structure and dielectric properties of Sr_1-3x/2Dy_xTiO₃ ceramics

The Sr_1-3x/2Dy_xTiO₃ (x = 0.005, 0.01, 0.015, 0.02, 0.04, 0.06) ceramics are prepared sintered in N₂ / air through a solid-state synthesis method. The effects of Dy doping amount and sintering process on the structure and dielectric properties of Sr_1-3x/2Dy_xTiO₃ ceramics were systematically investigated. We identify a novel Sr_1-3x/2Dy_xTiO₃ ceramic system sintered in N₂ that exhibits the most superior dielectric performance when x = 0.01. At room temperature, the ε_r and tanδ of Sr_0.985Dy_0.01TiO₃ ceramic sintered in N₂ are 29,000 and 0.07 at a frequency of 1 kHz, and 27,000 and 0.01 at a frequency of 10 kHz, respectively. Additionally, the ε_r of Sr_0.985Dy_0.01TiO₃ ceramics sintered in N₂ has an excellent temperature stability at high temperatures, with a change rate within the range of ± 15% at a frequency of 10 kHz ranging from 30 to 480 ℃. Through comparing Sr_0.985Dy_0.01TiO₃ ceramic sintered in air, sintering in N₂ significantly improved its ε_r and thermal stability. This study demonstrates that the improvement of processing techniques and doping strategies have enhanced the dielectric properties of the ceramics.