采用脉冲激光沉积方法,在氧化镁(MgO)单晶的(001)晶面上制备出钛酸钡(BaTiO3)/钛酸锶(SrTiO3)多层薄膜.利用高分辨透射电子显微镜(HRTEM)以及高角环形暗场(HAADF)像对其微观结构进行了详细研究,并探讨了多层膜的生长机制.结果表明:(1)在基体/薄膜界面附近存在周期性的失配位错,伯格斯矢量为a/2〈110〉；(2)界面附近存在界面层(过渡层),层内可能存在局部畴域；(3)薄膜内存在位移矢量为1/2〈 110〉的富Ti型和富Ba型两种层错；(4)薄膜生长过程中,由于弛豫产生的应变分布不均使得沉积原子倾向于在低应力处成核,最终多层膜显示柱状结构.%BaTiO3 ( BTO)/SrTiO3 (STO) superlattice thin films were grown on (001) MgO substrates using pulsed laser deposition. The microstructure and interfacial defects of the film were studied by means of high resolution transmission electron microscopy ( HRTEM) and High Angle Annular Dark Field STEM( HAADF-STEM). Based on the observation results, a growth mechanism of thernfilm was proposed- It is shown that ( I ) periodical misfit dislocations with a Burgers vector of a/2 < 110 > exist near the interface; ( II ) a very thin transitional interfacial layer appears at the film/substrate interface, in which local domains seem existed; ( IH ) two types of stacking faults exist in the film : Ti-rich and Ba-rich, and both of them have a Burgers vector of a/2 < 110 > ; ( IV ) during therngrowth, ununiform internal stresses resulted from relaxation make the BTO/STO superlattice thin film to form column structures.
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