摘要
采用传统固相法制备了xMgO-yCeO_2[摩尔百分比(mol%):x∶y=1∶1、1∶2和2∶1]二元系微波介质陶瓷,并研究了该体系的相组成、烧结性能和微波介电性能之间的影响关系。X射线衍射(XRD)结果表明,当烧结温度为1520~1680℃时,所研究组分范围内MgO-CeO_2二元系并未形成固溶体,均为MgO与CeO_2两相共存态;电子扫描显微镜带能谱仪(SEM-EDS)分析结果也进一步证实了这一现象的正确性。这说明,在MgO-CeO_2二元体系内,各组分反应的吉布斯标准自由能较高。此外,由矢量网络分析仪测试所得的微波介电性能可知,随着烧结温度的增加,MgO-CeO_2、2MgO-CeO_2和MgO-2CeO_2复相陶瓷的εr受温度的影响程度较小,而Q×f值(f=6.6~7.7 GHz)则呈先增后减趋势;其中,在1600℃烧结4 h时,该系列样品的τf值均处于(-59^-62)×10^(-6)/℃范围内。此外,以上分析结果也为MgO-CeO_2二元系相图的成分裁剪范围和构建提供了一定的实验依据。
xMgO-yCeO2[molar percentage（ mol%） ： x∶ y = 1 ∶ 1,1 ∶ 2 and 2 ∶ 1] binary microwave dielectric ceramic systems were prepared by the conventional solid-state reaction process,and the phase compositions,sintering properties and microwave dielectric of the sintered samples were investigated. The X-Ray Diffraction（ XRD） results show that the MgO-CeO2 systems within the scope of research components can not form solid solution phases,while the two-phase coexistence,CeO2 and MgO,was detected in the range of sintering temperature from 1520 ℃ to 1680 ℃. Additionally,the analysis results of the Scanning Electron Microscope with Energy Dispersive Spectrometer（ SEM-EDS） had also further confirm the validity of this phenomenon. It also means that the gibbs standard free energy of these relevant compound formations in MgO-CeO2 systems are relatively high. In addition,the microwave dilelectric properties measured by a vector network analyzer illustrate that the εrof the MgO-CeO2,2 MgO-CeO2 and MgO-2 CeO2 multiphase ceramics have only a little influence on sintering temperature,while the Q × f（ f = 6. 6-7. 7 GHz） values firstly increase and then decrease with an increase in sinteringtemperatures. Wherein,the τfvalues in these ceramic systems sintered at 1600 ℃ for 4 h are in the range of（-59--62） × 10^-6/℃. Moreover,some important experimental bases are provided for expanding the range of composition tailoring and designing binary phase diagram for MgO-CeO2 systems.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2017年第10期3417-3421,3438,共6页
Bulletin of the Chinese Ceramic Society
基金
国家自然科学基金(11464006)
广西高校中青年教师基础能力提升项目(KY2016YB534)
