γ-Y_2Si_2O_7陶瓷材料介电性能研究

以溶胶-凝胶法制备的纳米SiO2颗粒和微米Y2O3为原料,在高能行星磨上球磨混合粉末(摩尔比2∶1),冷压成型后烧结,制备出纯相γ-Y2Si2O7。借助X射线衍射、扫描电镜、能谱等方法研究了该材料的低温烧结行为。结果表明,该材料能够在1350℃下低温烧结出纯相γ-Y2Si2O7。用谐振腔法在X波段测试了γ-Y2Si2O7的介电性能。结果表明,该材料具有良好、稳定的介电性能。

Temperature-frequency dependence and mechanism of dielectric properties for γ-Y_2Si_2O_7

This paper reports that single-phase γ-Y2Si2O7 is prepared via a sufficient blending and cold-pressed sintering technique from Y2O3 powder and SiO2 nanopowder. It studies the dielectric properties of γ-Y2Si2O7 as a function of the temperature and frequency. The γ-Y2Si2O7 exhibits low dielectric loss and non-Debye relaxation behaviour from 25 to 1400℃ in the range of 7.3 18 GHz. The mechanism for polarization relaxation of the as-prepared γ-Y2Si2O7 differing from that of SiO2 is explained. Such particular dielectric properties could potentially make specific attraction for extensive practical applications.

多孔氮化硅表面γ-Y_2Si_2O_7陶瓷涂层的制备及抗热震性能

采用浆料喷涂与高温熔渗结合的方法,以γ-Y_2Si_2O_7和Y_2O_3-Al_2O_3-SiO_2三元氧化物粉体为原料,在多孔Si_3N_4表面制备致密γ-Y_2Si_2O_7陶瓷涂层,采用XRD和SEM测试方法系统研究原料配比及烧结温度对涂层结构、组织和抗热震性能的影响。结果表明:SiO2与Al2O3物质的量之比较高时,涂层为致密γ-Y_2Si_2O_7层和过渡层的双层结构;SiO_2与Al_2O_3物质的量之比较低时,只能形成单层结构;双层结构涂层的抗热震性能优于单层结构涂层。