摘要
以硝酸盐为前驱体、NH3·H2O-NH4HCO3为复合沉淀剂，采用缓冲溶液法制备了含4％～12％（摩尔分数）Sm2O3的ZrO2粉体。通过X射线衍射、透射电镜及比表面吸附法等对所得粉体的相结构、形貌和粒度进行了测定。所得粉体经冷等静压成形后，在1300～1500℃下烧结5h，得到烧结体。采用阿基米德法（水介质）测定了烧结体的密度，采用扫描电镜对烧结体的微结构进行了观测，并通过交流阻抗谱法测定了烧结体的电导率。实验结果表明：当Sm2O3掺杂量大于8％时，在600℃煅烧共沉淀物可得到具有立方结构的氧化钐稳定氧化锆（SSZ）粉体，其颗粒形状规则，粒径在10～20nm。随着Sm2O3掺杂量的增加和烧结温度的升高，烧结体的相对密度增加，1500℃烧结的掺杂12％Sm2O3的ZrO2（12SSZ）烧结体的相对密度为96．91％。在500～800℃的测量范围内，SSZ烧结体的电导率与温度成线性关系，12SSZ在800℃时的电导率可达0．043S·cm^-1，电导活化能为0．72eV。
Zirconia stabilized with 4% - 12% （mole fraction） samaria （4 - 12 SSZ） powders were synthesized by a buffer-solution method. Phase constitute, particle size and morphology of the synthesized powders was characterized by X-ray diffraction （XRD）,transmission respectively. and sintered electron microscopy （TEM） and BET, The powders were cold isostatic pressed at 1300 - 1500 ℃ for 5 h. Density of the sintered SSZ samples was measured by the Archimedes method and were expressed as relative to the theoretical value, and microstructure was observed by scanning electron microscope （SEM）. Electrical conductivity and conductive activation energy of the sintered SSZ samples were also tested in the temperature range 500- 800 ℃ in air by alternating-current impedance spectroscopy. The results show that SSZ powders with single fluorite phase can be obtained by calcining the coprecipitates at a relatively low temperature of 600℃. The powders have regular particle shape with an average particle size of 10 - 20 nm. The samaria amount and the calcination temperature also have a great influence on the phase formation. Density of the sintered SSZ samples increases as sintering temperature and Sm2O3 doping amount increase. A relative density of 96.91% is obtained for the 12 SSZ sample sintered at 1500 ℃. Electrical conductivity of the sintered SSZ samples increases with temperature. The 12 SSZ sample sintered at 1500 ℃ has an ionic conductivity of 0. 043 S· cm^- 1 and a conductive activation energy of 0.72 eV at 800 ℃ in air.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2007年第1期39-44,共6页
Journal of the Chinese Society of Rare Earths
基金
国家自然科学基金(20271047)
合肥工业大学中青年创新群体基金(103-037016)
合肥工业大学学生创新基金(XS05016)资助项目
关键词
缓冲溶液法
氧化钐稳定氧化锆
纳米粉体
离子电导率
电导活化能
稀土
buffer-solution method
samaria stabilized zirconia （SSZ）
nanosized powders
ionic conductivity
conductive activation energy
rare earths
