非对称界面耦合对LaCoO3/LaMnO3 双层膜性能调控研究

Influence of Asymmetric Interface Coupling on Properties of LaCoO3/LaMnO3 Bilayers

摘要:

通过高分子辅助溶胶凝胶自旋涂沉积法在（100）取向的SrTiO₃衬底上制备出LaCoO₃/LaMnO₃双层膜。在LaMnO₃表面生长一层LaCoO₃膜后，由于二者结构对称性差异，最终会在膜层界面处形成非对称界面耦合。由于非对称耦合作用，双层膜的铁磁转变温度从单层LaMnO₃的262 K下降为200 K。此外，由于界面处Mn-O-Co的双交换作用，与单层LaMnO₃薄膜的矫顽场相比，双层膜的矫顽场增大了约500%。研究结果表明，不同结构和性质的薄膜重组为多层膜的基础研究和高性能功能材料的应用提供了一种新的结构设计途径。

Abstract:

The LaCoO₃/LaMnO₃ bilayers epitaxial film grown on (100) SrTiO₃ substrates were obtained by a simple polymer assisted sol-gel deposition method. Growing a LaCoO₃ layer on the top of LaMnO₃ leads to the asymmetric interface coupling at the interface layer due to their difference in strucural symmetry, and reduces the ferromagnetic transition temperature caused by the asymmetric interface coupling effect from 262 K to 200 K. In addition, compared with the coercive field of isolated LaMnO₃ film, the coercive field observed in the bilayers is increased by ~500% due to a strong ferromagnetic Mn-O-Co double exchange interaction at the interface. The results demonstrate that the recombination of multilayer films with different properties provides a new way to design functional materials for fundamental studies or demanding applications.