Ce_(1-x)M′_xCa_(0.2)O_(1.8-0.4x)(M=Y,La和Gd)的水热合成及离子导电性质研究

Hydrothermal Synthesis and Ionic Conduction Properties of Ce_(1-x) M′_xCa_(0.2) O_(1.8-0.4x)(M=Y, La and Gd)

采用水热法合成了系列双掺杂的萤石结构 Ce1 - x Lnx Ca0 .2 O1 .8- 0 .4x固溶体 ,并研究了 3种稀土离子对固溶体导电性的影响 ,发现掺杂离子半径接近 Ce4+时 ,体系电导率增大而活化能降低 .同时发现水热合成的Ce1 - x Lnx Ca0 .2 O1 .8- 0 .4x样品的平均粒度按着掺入离子 Y3+ ,Gd3+ ,La3+ 的顺序逐渐减小 ,分别为 32 ,2 0和1 5 nm.这种变化是由于 Y3+ 半径比 La3+ 和 Gd3+ 更接近 Ce4+ ,因而在水热合成过程中 ,掺 Y3+ 的体系更有利于晶粒的生长 。

A series of lanthanide co doped ceria solid solution, Ce 1- x M′ x Ca 0. 2 O 1.8-0.4 x (M=Y, La and Gd) has been prepared by mild hydrothermal method at 240 ℃ for less than 24 h. The doping effect of lanthanide on the conduction properties was investigated. It is found that the conductivity increased from Y, Gd to La, whereas the activation energy changed in a reverse trend. It is also found that the mean particle size decreases from Y, Gd to La, they are 32 nm, 20 nm and 15 nm, respectively. All these results can be contributed to the size similarity of Y 3+ and Ce 4+ .