La_2O_3和Sm_2O_3掺杂对SrTiO_3陶瓷结构与性能的影响

Effects of La_2O_3 and Sm_2O_3 doping on structure and properties of SrTiO_3 ceramics

对SrTiO3陶瓷分别进行了La2O3和Sm2O3微量掺杂改性研究,观察了稀土掺杂后陶瓷样品的显微结构,研究了其介电损耗、相对介电常数及电容量变化率随测试温度变化的规律,分析了样品在不同测试电压下的绝缘特性。研究结果表明,La2O3和Sm2O3的微量掺杂对SrTiO3陶瓷的影响相似。稀土掺杂后,样品的晶粒尺寸变小,介电损耗增大,相对介电常数明显提高,电容量变化率明显改善,绝缘电阻明显减小。当稀土掺杂量高于0.2%(摩尔分数)时,La2O3的细晶效果比Sm2O3更明显。

The SrTiO3-based ceramics doped with La2O3 or Sm2O3 were studied. The microstructures of the doped samples were observed. The change laws of dielectric loss, relative permittivity and capacitance change rates with test temperature were studied. The insulating properties at different test voltages were analyzed. The results show that, effects of La2O3 and Sm2O3 doping on SrTiO3-based ceramics are analogous. After doping of these two rare earths, the samples＇ average grain size becomes smaller, the dielectric loss increases, the relative permittivity increases evidently, the capacitance change rate improves obviously, and the insulation resistance decreases significantly. The effect of inhibiting grain growth by La2O3 is more obvious than that by Sm2O3 when the doping amount is more than 0.2 % （mole fraction）.