MgO/Eu_2O_3共掺杂对Al_2O_3陶瓷微波介电性能的影响  

Effect of MgO/ Eu_2O_3 Co-doping on the Microwave Dielectric Properties of Al_2O_3 Ceramics

作　　者：张康[1] 李蔚[1] 林慧兴[2] 

机构地区：[1]华东理工大学材料科学与工程学院,上海200237 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《无机材料学报》2015年第9期984-988,共5页Journal of Inorganic Materials

摘　　要：利用湿化学法制备了MgO/Eu2O3共掺Al2O3陶瓷,研究了不同的MgO/Eu2O3掺杂量对Al2O3陶瓷物相组成、显微结构和微波介电性能的影响。结果表明:适量的MgO/Eu2O3共掺有助于Al2O3的致密化和晶粒生长。在介电性能方面,MgO/Eu2O3共掺对Al2O3陶瓷的介电常数没有明显的影响,但对介电损耗的影响显著。随着Eu2O3含量的增加,Al2O3陶瓷的Q×f值会呈现先增加后下降的变化趋势。0.05wt%MgO/0.10wt%Eu2O3共掺的样品在1590℃下保温4 h获得的微波介电性能最佳,εr^9.82,Q×f^225,225 GHz。Q×f值的这种变化可能与样品微观结构的变化相关。先是随着MgO/Eu2O3共掺量的增加,晶粒尺寸不断增加,晶界不断减少,这有利于Q×f值的提高;接着,当MgO/Eu2O3共掺量进一步增加时,晶粒尺寸不断下降,晶界增多,这会导致样品Q×f值的降低。另外,应力和第二相也可能对Q×f值的变化产生影响。Al2O3 ceramics co-doped with MgO/Eu2O3 were prepared by wet chemical process. The effects of the content of MgO/Eu2O3 co-doping on phase composition, microstructure and microwave dielectric properties of Al2O3 ceramics were explored. The experimental results show that suitable contents of MgO/Eu2O3 can promote densification and grain growth of Al2O3. As to the dielectric properties, the influence of MgO/Eu2O3 co-doping on the dielectric constant can be ignored. However, it has a significant impact on the dielectric loss. The Q×f value increases initially and then decreases as the Eu2O3 content increases.Optimized microwave dielectric properties with εr^9.82, Q×f ~225,225 GHz. can be attained for the samples co-doped with 0.05wt% MgO/0.10wt% Eu2O3 sintered at 1590℃ for 4 h This change of Q×f value may relate to the change of sample’s microstructure. Firstly, when the content of MgO/Eu2O3 increases, the grain size increases and the grain boundary decreases, which is beneficial to increase the Q×f value. Then, as the content of MgO/Eu2O3 keeps increase, the grain size decreases and the grain boundary increases, which may lead to decrease Q×f value. In addition, the presence of strain and second phase may also influence the change of Q×f value.

关 键 词：氧化铝 MgO/Eu2O3共掺 微波介电性能 

分 类 号：TQ174[化学工程—陶瓷工业]