电子束辐照下LaCoO3/LaMnO3多层膜的结构演化

Structural evolution of LaCoO3/LaMnO3 multilayers under electron beam irradiation

本文利用扫描透射电子显微学方法,表征了在压应力铝酸镧及拉应力钛酸锶衬底生长的LaCoO3/LaMnO3多层膜中的应变分布,研究了在电子束辐照作用下LaCoO3/LaMnO3多层膜的结构演化。LaMnO3层中压应变引起的缺陷在电子束辐照下会得到愈合,LaCoO3层在电子束辐照下会产生更多的暗条纹。电子能量损失谱的结果表明,辐照前后LaCoO3,LaMnO3层中辐照区域均会产生更多的氧空位。本文研究的多层膜中的结构演化是应变能、电子束辐照的能量以及氧空位形成能共同作用的结果。本文也为电子束辐照调控LaCoO3薄膜的磁性提供了可能。

By using scanning transmission electron microscopy,the strain distribution in LaCoO3/LaMnO3 multilayers epitaxially grown on tensile SrTiO3 substrate and compressive LaAlO3 substrate is studied.The structural evolution of LaCoO3/LaMnO3 multilayers is investigated by in-situ electron beam irradiation(EBI).The results show that the compressive strain induced defects in LaMnO3 layer can be healed by EBI,and EBI can create more dark stripes in the LaCoO3 layer.The analysis of the electron energy loss spectroscopy reveals that oxygen vacancies exist in both LaCoO3 and LaMnO3 layers after EBI.In this study,the microstructural change is the result of the competition among strain energy,EBI induced energy and the forming energy of oxygen vacancy.This work paves a way to tune the magnetism of LaCoO3 related films.