Nd_2O_3掺杂对BSTO/MgO复合陶瓷显微结构和性能的影响(英文)

Influence of Nd_2O_3 Doping on the Dielectric Properties of BSTO/MgO

在钛酸锶钡(BSTO)与质量分数为58%的MgO混合的基础上,采用固相反应法制备了未掺杂Nd2O3和掺杂(0.3,0.5,0.7,1.5mol%)的Ba0.55Sr0.45TiO3/MgO复合陶瓷材料,并研究了它们的显微结构和介电性能。XRD和SEM分析显示,BSTO/MgO复合陶瓷材料只有钙钛矿相,并随着Nd2O3掺杂量的增加,BSTO/MgO复合陶瓷材料晶粒变小。研究结果表明,掺杂适量Nd2O3可以减少BSTO/MgO复合陶瓷材料的高频损耗,并且保持适当的介电常数,但过量掺杂Nd2O3会降低介电常数。当掺杂0.3mol%Nd2O3时,BSTO/MgO复合陶瓷材料的介电常数为88,损耗2.8×10-3(4.1GHz),介电常数可调为6.9%(2.0kV/mm)。利用电介质理论分析了Nd2O3对BSTO/MgO复合陶瓷材料介电性质的改性机理。

Based on w （MgO） % = 58% magnesia mixed with Ba0.55 Sr0 .45 TiO3 （BSTO） , undoped and Nd2O3 doped （0.3, 0.5, 0.7, 1.5mol% ） Ba0.55Sr0 45TiO3/MgO composite were prepared by traditional ceramic process-solid phase synthesis and their microstructure and dielectric properties were systemically studied. XRD and SEM analyses showed that the BSTO/MgO composite containd a pure perovskite phase and the grain size of BSTO/MgO composite became smaller with the increasing of the amount of Nd2O3. It was found that proper amount of Nd2O3 could reduce the loss tangents of BSTO/MgO composite at high frequency and ensured moderate dielectric constant. However, excessive amount of Nd2O3 would lower dielectric constant. The BSTO/MgO composit with 0. 3mol% Nd2O3 possesses excellent dielectric properties ： εt = 88, tanδ = 2.8 × 10^ -3 （ at 4.1 GHz） and tunability = 6.9% （ at external DC field E = 2.0 kV/mm）.