Abstract:

Ultrafine Ce_0.8Sm_0.2O_1.9 (SDC) solid solution powders were prepared by the combination of sol-gel process and self-propagating low temperature combustion synthesis with glycine as reductant and metal nitrates as oxidant.The phase identification, morphology and specific surface area of SDC powders were investigated by XRD, SEM and BET method, respectively.The results showed that SDC powders calcined at 600℃ with crystallites in the 13—30 nm ranges had a pure cubic fluorite crystalline structure.It was found that the molar ratio of glycine to metal nitrate had a great effect on both the morphology and sinterability of the powders.When the molar ratio of glycine to metal nitrate was 2 and 3, the SDC powders possessed a loose structure.The powders had good sinterability in the experiment and the sintered specimens with relative density up to over 95% could be prepared by sintering at 1400℃ for 2 h.The average grain size of the sintered specimens was 0.5 μm.

Key words: FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-hansi-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">溶胶FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体" lang=EN-US>-FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-hansi-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">凝胶法；低温燃烧合成；掺杂氧化铈；固溶体；甘氨酸

摘要：

用甘氨酸作还原剂、硝酸盐作氧化剂，采用溶胶-凝胶与自蔓延低温燃烧相结合的方法制备了超细Ce_0.8Sm_0.2O_1.9 (SDC)固溶体，对所合成的粉体分别采用XRD、SEM和BET法进行了表征。结果表明，600℃焙烧产物是具有较高相纯度的单一立方相萤石型结构固溶体，根据XRD估算晶粒度为13～30 nm。甘氨酸与金属硝酸盐(G/N)摩尔比对粉体的微观形貌和烧结性能有很大影响， 当G/NFONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-hansi-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">溶胶FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, mso-fareast-font-family: 宋体" lang=EN-US>-FONT-SIZE: 10.5pt, mso-bidi-font-size: 11.0pt, mso-ascii-font-family: Times New Roman, mso-hansi-font-family: Times New Roman, mso-bidi-font-family: Times New Roman, mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">凝胶法；低温燃烧合成；掺杂氧化铈；固溶体；甘氨酸