【作者】 卢歆；

【导师】 张希艳；

【作者基本信息】 长春理工大学 ， 凝聚态物理， 2008， 硕士

【摘要】 Yb³⁺：Y₂O₃激光透明陶瓷是一种新型激光工作物质，展示了潜在的应用前景。为了制备性能优异的陶瓷材料，其先决条件是制备出粒度均匀、分散性好、尺度小的超细Yb³⁺：Y₂O₃粉体。本文采用液相共沉淀法与低温燃烧法制备Yb³⁺：Y₂O₃超细粉体。采用XRD、TG-DTA、TEM、FT-IR及荧光光谱分析等手段表征了Yb³⁺：Y₂O₃超细粉体。系统地研究了共沉淀法中起始pH值、NH₄HCO₃的滴加速度、表面活性剂、反应温度、保温时间、陈化时间、Yb离子掺杂量等因素对Yb³⁺：Y₂O₃粉体形貌、粒径大小及性能的影响，并对共沉淀法制备超细粉体中的团聚问题进行分析。在低温燃烧法中考察了点火温度、燃料用量和热处理温度对所获得的粉体特性的影响。结果表明，采用共沉淀法制备Yb³⁺：Y₂O₃超细粉体的粒径在100～200nm，最佳工艺参数是8<pH<9，采用反向滴定法，滴定速度小于2ml／min．，（NH₄）₂SO₄为表面活性剂其加入量为Y（NO₃）₃摩尔数的5％，煅烧温度1100℃，保温时间4小时，Yb掺杂浓度为3at．％，514nm激发的荧光光谱有三个发光峰，峰值分别是976nm、1030nm和1075nm，其中1030nm发射峰最强，对应于Yb³⁺离子的²F_5／2→²F_7／2发光跃迁。采用无水乙醇为分散剂，可以显著改善颗粒的团聚现象。以低温燃烧合成技术制备Yb³⁺：Y₂O₃超细粉体的粒径为15～30nm，得到较佳的工艺参数：硝酸盐：尿素=1：3，点火温度600℃。更多还原

【Abstract】 Yb³⁺:Y₂O₃ ceramics is a new candidate for high power laser. Obtaining ultrafine powders with uniform size and good dispersion are the prerequisite for preparing transparent Yb³⁺:Y₂O₃ ceramics with high optical quality. In this thesis the liquid phase co-deposited method and LCS method were adopted to prepare the Yb³⁺:Y₂O₃ ultrafine powders.XRD, TG-DTA, TEM, FT-IR and the fluorescence spectra analysis were employed to characterize the Yb³⁺:Y₂O₃ ultrafine powders. The influences of seven factors, including initial pH value , anti-aggregative agent, reaction temperature, holding time, Yb ion content on the morphology, size and property of the powders were systematically studied. The agglomeration phenomenon of the powders prepared by the co-precipitation method was analyzed. The influences of ignition temperature, fuel content and calcination temperature on the characteristics of the powders were investigated for the LCS method.The particle diameters of Yb³⁺:Y₂O₃ ultrafine powders synthesized by the co-precipitation method were about 100 - 200nm. The optimum technology parameters were obtained as followings. The pH value is between 8 and 9. The titration velocity should be less than 2ml per minute. Surfactant （NH₄）₂SO₄ was 5mol% to Y（NO₃）₃. The calcining temperature and time of the powders were 1100℃and 4 hours, Yb content is 3at.%. The luminescence spectrum is consisted of three peaks at 976nm, 1030nm and 1075nm respectively under excitation of 514nm which is attributed to transition of ²F_5/2→²F_7/2 of Yb³⁺. Among the three peaks 1030nm showed the strongest intensity.. Absolute ethyl alcohol decreased the conglobation phenomenon of the ultrafine powders. The particle diameters of Yb³⁺:Y₂O₃ ultrafine powders prepared by using the LCS method were about 15-30nm. The optimum technology parameters of LCS were that the value of nitrate : urea was 3:1, and the ignition temperature was about 600℃.更多还原