外延生长的Gd掺杂CeO2薄膜内位错的透射电子显微学表征

摘要

利用脉冲激光沉积（ pulsed laser depositon， PLD）方法在YSZ（ Y2 O3 stabilised zirconia）单晶衬底上外延生长了Gd掺杂的CeO2薄膜（gadolinium doped CeO2，GDC）。利用透射电子显微镜（TEM）对GDC／YSZ界面以及GDC薄膜内部的位错结构进行了表征。实验发现，界面处存在周期性分布的失配位错，界面失配主要通过失配位错释放。 GDC薄膜内部存在两种不同的位错，其中一种为纯刃型位错，另外一种为混合型位错。%Epitaxial Gd⁃doped CeO2(GDC) films grown on Y2O3⁃stabilised ZrO2(001) (YSZ) substrates by pulsed laser deposition ( PLD ) were investigated by transmission electron microscopy ( TEM ) and high⁃resolution transmission electron microscopy ( HRTEM) . Selected area diffraction ( SAD) patterns showed a cubic⁃on⁃cubic orientation relationship between the GDC films and the YSZ substrates. A semi⁃coherent interface with periodic misfit dislocations was revealed by HRTEM when imaged from [ 100 ] direction. The interface misfit dislocations at the interface were supposed to be the main mechanism for the strain relaxation of the interface . Two types of dislocations with Burgers vector b=1/2〈011〉 in GDC films were also revealed by HRTEM:one was pure edge dislocation and the other was a mixed type.