Interfacial coupling, oxygen deficiency, and orbital reconstruction in oriented La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$/DyMnO${}_3$ bilayers

The orthorhombic La${}_{0.7}$Ca${}_{0.3}$MnO${}_3$/DyMnO${}_3$ (LCM/DMO) bilayers and referenced LCM single-layer films were epitaxially deposited by polymer-assisted deposition on (001)- and (011)-oriented SrTiO${}_3$ (STO) substrates, respectively, and the effects of interfacial coupling, oxygen deficiency, and orbital reconstruction on the physical properties of the LCM/DMO bilayers have been investigated. It is found that the magnetic and transport properties of LCM/DMO bilayers are weaker than those of LCM referenced films, due to the orientation-adjusted interfacial coupling and oxygen deficiency. More importantly, the introduced larger strain from DMO layer promotes the eg orbital splitting with consequences for orbital reconstruction and the enhancement of antiferromagnetic phase in LCM layer, which strongly affects the physical properties of LCM/DMO bilayers cooperated with interfacial coupling and oxygen deficiency.