掺Sr铬酸镧粉体的合成及低温烧结行为研究  

Synthesis and Low-temperature Sintering Behavior of Sr-doped Lanthanum Chromite Powders

作　　者：刘伟明[1] 李胜利[1] 李士刚[1] 王笑[1] 

机构地区：[1]山东大学材料科学与工程学院,济南250061

出　　处：《无机材料学报》2007年第6期1061-1064,共4页Journal of Inorganic Materials

基　　金：高等学校博士学科点专项基金(20050422026);山东省自然科学基金(Y2005F20)

摘　　要：通过溶胶-凝胶法制备了La_(1-x)Sr_xCrO_3纳米粉体并实现了低温致密烧结,用X射线衍射仪、透射电镜、差示扫描量热分析仪和扫描电镜对粉体和烧结体进行分析.结果表明:粉体的平均直径<50nm,当x=0,0.1时,粉体为单一的La_(1-x)Sr_xCrO_3,x=0.3时存在第二相SrCrO_4.Sr掺杂使铬酸镧晶格产生畸变,随Sr含量的增加,晶格常数逐渐变小.铬酸镧纳米粉体的烧结分为两个阶段,1200℃以前的缓慢放热和1350℃左右的较快放热,分别对应烧结的初期和中期.依据DSC分析结果制订了烧结工艺,并在1380℃烧结得到相对密度91%的铬酸镧烧结体.La1-xSrxCrO3 powders were synthesized by a sol-gel method and sintered at a low temperature. The powders and sintered pellets were characterized by XRD, TEM, DSC and SEM. It is found that the mean particle size is below 50nm. The powder with x=0 and 0.1 of single phase of La1-xSrxCrO3, and another phase SrCrO4 appears with x=0.3. Lattice distorts and lattice parameters of lanthanum chromite decrease with increasing Sr content. The sintering process of lanthanum chromite can be divided into two stages： a slow exothermic effect below 1200℃ and a quick exothermic effect near 1350℃, corresponding to the primary and intermediate sintering stage, respectively. The relative density of the sintered body （x=0.3） after sintering at 1380℃ is 91%, according to the procedure derived from the DSC analysis.

关 键 词：铬酸镧 溶胶-凝胶 稀土 烧结 

分 类 号：TB383[一般工业技术—材料科学与工程] TF12[冶金工程—粉末冶金]