Yuan Long-Fei, Zhang Ting, Han Dan-Dan
College of Physics and Electronic Science, Zunyi Normal University, Zunyi, 563002, Guizhou, China.
College of Chemistry and Chemical Engineering, Zunyi Normal University, Zunyi, 563002, Guizhou, China.
Sci Rep. 2023 Sep 15;13(1):15285. doi: 10.1038/s41598-023-42610-3.
NaEuCuTiO and NaSmCuTiO dielectric ceramics were synthesized at different sintering temperatures (950, 975 and 1000 °C) by a solid-state reaction method. Phase structure, cation valence state, and dielectric properties of all sintered ceramics were systematically investigated. When the preparation temperature was changed, the Cu ion concentration of (Na, Eu) co-doped ceramics changed faster than that of (Na, Sm) co-doped ceramics. Abnormally high dielectric constants of ~ 3.17 × 10 and ~ 1.06 × 10 (at 10 Hz and 303 K) were achieved in NaSmCuTiO and NaEuCuTiO ceramics prepared at 950 °C, respectively. However, NaSmCuTiO and NaEuCuTiO prepared in high sintering temperature (1000 °C) exhibited a good frequency stability of dielectric permittivity. It was demonstrated that an increasing number of charge carriers induced by the increase of sintering temperature could lead to a competitive coexistence of two polarization mechanisms (surface barrier layer capacitor and internal barrier layer capacitor), further changing the dielectric properties of CaCuTiO-based ceramics.
通过固态反应法在不同烧结温度（950、975和1000°C）下合成了NaEuCuTiO和NaSmCuTiO介电陶瓷。系统研究了所有烧结陶瓷的相结构、阳离子价态和介电性能。当制备温度改变时，（Na，Eu）共掺杂陶瓷的Cu离子浓度变化比（Na，Sm）共掺杂陶瓷更快。在950°C制备的NaSmCuTiO和NaEuCuTiO陶瓷中，分别在10Hz和303K时实现了异常高的介电常数，约为3.17×10和1.06×10。然而，在高烧结温度（1000°C）下制备的NaSmCuTiO和NaEuCuTiO表现出良好的介电常数频率稳定性。结果表明，烧结温度升高引起的载流子数量增加会导致两种极化机制（表面势垒层电容器和内部势垒层电容器）的竞争共存，进而改变CaCuTiO基陶瓷的介电性能。
