【摘要】 溶剂热法制备的0.3%Tm₂O₃掺杂K_0.5Na_0.5Nb_0.7Ta_0.3O₃陶瓷粉体经常压烧结工艺烧结成陶瓷。系统研究了烧结时间和温度对陶瓷相结构、致密度、显微结构以及介电性能的影响。结果表明:烧结温度和保温时间对陶瓷的室温晶体结构几乎没有影响,所有的陶瓷样品均为单一的钙钛矿结构,但对其表面形貌、密度以及介电性能的影响较大。烧结温度为1180℃,在1～2 h范围内,随着保温时间的延长,陶瓷密度不断增大,介电常数增加;烧结时间为2h,在1180～1200℃范围内,随着烧结温度的不断增加,陶瓷的致密度和介电性能先增加后降低,1185℃保温2h时,陶瓷获得良好的介电性能:ε_r100kHz=1900,tanδ_100kHz=0.022,T_C=182℃。更多还原

【Abstract】 The 99.7%K_0.5Na_0.5Nb_0.7Ta_0.3O₃·0.3%Tm₂O₃ ceramic powders prepared by solvothermal method was sintered into ceramics by pressure sintering process.The effects of holding time and sintering temperature on phase structure,microstructure,density and dielectric properties were systematically investigated.The results show that sintering temperature and holding time have little effect on the room temperature crystal structure of ceramic and all the specimens exhibit a pure perovskite structure which strongly affects the surface morphology,density and dielectric properties.When sintered at 1180℃ for 1-2 h,the density and dielectric constant increase with the extension of holding time;when sintered at 1180-1200℃ for 2 h,with the increase of sintering temperature,the density and dielectric properties of ceramics first increase and then decrease.The 0.3% Tm₂O₃ doped99.7%K_0.5Na_0.5Nb_0.7Ta_0.3O₃ ceramic sintered at 1185℃ for 2 h exhibits excellent properties:ε_r100kHz=1900,tanδ_100kHz=0.022,T_C=182 ℃.更多还原