Extended phase diagram of La1–x Ca x MnO3 by interfacial engineering*

Abstract

The interfacial enhanced ferromagnetism in maganite/ruthenate system is regarded as a promising path to broaden the potential of oxide-based electronic device applications. Here, we systematically studied the physical properties of La1−x Ca x MnO3/SrRuO3 superlattices and compared them with the La1−x Ca x MnO3 thin films and bulk compounds. The La1−x Ca x MnO3/SrRuO3 superlattices exhibit significant enhancement of Curie temperature (T C) beyond the corresponding thin films and bulks. Based on these results, we constructed an extended phase diagram of La1−x Ca x MnO3 under interfacial engineering. We considered the interfacial charge transfer and structural proximity effects as the origin of the interface-induced high T C. The structural characterizations revealed a pronounced increase of B–O–B bond angle, which could be the main driving force for the high T C in the superlattices. Our work inspires a deeper understanding of the collective effects of interfacial charge transfer and structural proximity on the physical properties of oxide heterostructures.