摘要
采用固相反应法制备(Mg1-xZnx)2SiO4(0≤x≤1)微波介质陶瓷,研究(Mg1-xZnx)2SiO4陶瓷在0≤x≤1范围内的相演变、微结构与其微波介电性能间相互关系.XRD测试结果表明:橄榄石结构的Mg2SiO4与硅矽矿结构的Zn2SiO4在晶体结构上存在很大差别,(Mg,Zn)2SiO4在0≤x≤1范围内只能部分地实现有限固溶.背散射电子扫描显微镜(BESEM)测试结果显示:随着x的增加,MgSiO3第二相得到抑制;陶瓷出现液相烧结,促进晶粒生长与玻璃相在晶界处沉积.微波介电性能测试结果表明:由于Zn2+离子极化能力大于Mg2+离子,(Mg1-xZnx)2SiO4(0≤x≤1)陶瓷介电常数随x值增加而增大;0≤x≤1范围内,Mg2SiO4陶瓷微波性能由于第二相、气孔率增加与晶粒增大而降低,Zn2SiO4陶瓷由于微结构得到改善,陶瓷微波性能得到优化.当x=0.6时,得到较好的(Mg0.4Zn0.6)2SiO4陶瓷微波性能为:εr=6.6,Qf=95650GHz,τf=-60×10-6/℃.
The phase evolutions,microstructures,and microwave dielectric properties of(Mg1-xZnx)2SiO4(0≤x≤1) ceramics were investigated.The XRD results show that Mg2SiO4 and Zn2SiO4 are partly limited solid solution in the systems of(Mg1-xZnx)2SiO4 ceramics,due to the large differences between their crystal structures.BESEM images show that with the increases of x,the second phase of MgSiO3 will be suppressed,and the occurrence of liquid phase sintering accelerates the growth of crystal grain and aggradations of glass phase in the boundary of grain.The dielectric constants of(Mg1xZnx)2SiO4 ceramics gradually increase because of the polarization of Zn2+ ion is larger than that of Mg2+ ion.The microwave properties of(Mg1-xZnx)2SiO4 ceramics change with the variant of x value,together with external factors of the secondary phase,porosity and grain size of(Mg1-xZnx)2SiO4 ceramics.When x is equal to 0.6,the optimum microwave dielectric properties of(Mg0.4Zn0.6)2SiO4 ceramics is obtained:εr=6.6,Qf=95650GHz,τf=-60×10-6/℃.
出处
《无机材料学报》
SCIE
EI
CAS
CSCD
北大核心
2010年第3期255-258,共4页
Journal of Inorganic Materials
基金
浙江省自然科学基金(Y1090765
Y1090146)
浙江省科技计划项目(KYZ044308038)
校启动基金(KYS04560819)