溶胶-凝胶法制备Y2O3掺杂ZnO压敏薄膜及其电性能（英文）

研究溶胶-凝胶法制备不同浓度Y2O3掺杂对ZnO-Bi2O3压敏薄膜微观结构和电性能的影响。研究结果表明:Y2O3掺杂ZnO薄膜在750°C空气气氛下退火1h,ZnO薄膜的特征峰与ZnO的六方纤锌矿结构相匹配;ZnO晶粒直径随着掺杂量的增加而减小,Y2O3稀土掺杂氧化锌晶粒细化;薄膜厚度均匀且每一层厚度约80nm。研究结果还表明:当Y3+掺杂浓度为0.2%(摩尔分数)时,ZnO薄膜的非线性伏安特性最好,其漏电流为0.46mA,电位梯度为110V/mm,非线性系数为3.1。     

丝网印刷和烧结工艺对陶瓷基复合材料微带天线膜层结构与性能的影响

目的 研究丝网印刷工艺参数（印刷压力、离网间距和印刷速度）和烧结制度（烧结温度和保温时间）对陶瓷基复合材料微带天线基板表面丝网印刷银膜层结构与性能的影响。方法 在石英纤维增强二氧化硅基复合材料表面,通过丝网印刷工艺,在指定温度下烧结制备银膜层。采用金相显微镜、扫描电镜、四探针测试仪和焊接法等测试手段,研究银膜层的微观形貌、方阻与附着力。采用矢量网络分析仪表征微带贴片天线的驻波性能。结果 当印刷压力为90N、离网间距为2.5mm、印刷速度为90mm/s时,银膜层的方阻最低,附着力最大。当烧结温度为850℃、保温时间为15 min时,银膜可以获得最好的致密结构和导电性,此时方阻为5.4 m?/□,附着力为2.25 N/mm²。在上述印刷和烧结工艺条件下制作的天线板,其常温中心频点为1.869GHz,与设计中心频点（1.86GHz）的吻合度较好。结论 丝网印刷工艺参数通过影响印刷过程中银浆的转移率影响膜层的导电性和附着力,烧结制度显著影响银膜结构的致密性,进而影响银膜的导电性和附着力。在印刷压力为90 N、离网间距为2.5 mm、印刷速度为90 mm/s的印刷工艺条件和...     

Effects of Eu2O3 doping on microstructural and electronic properties of ZnO-Bi2O3-based varistor ceramics prepared by high-energy ball milling0推荐

ZnO-Bi2O3-based varistor ceramics doped with EU2O3 in a range from 0 to 0.4% were obtained by high-energy ball milling and fired at 900-1000 ℃ for 2 h. XRD and SEM were applied to determine the phases and microstructure of the varistor ceramics. A DC parameter instrument was applied to investigate the electronic properties and V-I characteristics. The XRD analysis of Eu2O3-doped ZnO-Bi2O3-based varistor ceramics shows that the ZnO, Eu-containing Bi-rich, Zn7Sb2O12-type spinel and Zn2Bi3Sb3O14-type which is the pyrochlore phase are present. With increasing Eu2O3 content, the average size of ZnO grain firstly decreases and then increases. The grain boundary defect model was particularly used to explain the excellent nonlinearity of ZnO-Bi2O3-based varistor ceramics with the addition of0.1% Eu2O3 and sintered at 950 ℃.