Abstract
The emergence of magnetism unique to the interface between the multiferroic BiFeO3 (BFO) and ferromagnetic La1-xSrxMnO3 (LSMO) offers an opportunity to control magnetism in nanoscale heterostructures with electric fields. In this paper, we investigate the influence of chemical composition and crystallographic orientation on the interfacial magnetism of BFO/LSMO superlattices. Our results reveal that the induced net magnetic moment in the BFO layers increases monotonically with increasing saturation magnetization of the LSMO layers. For the (100)-BFO/LSMO (x=0.2) superlattice, the induced moment reaches a record high value of ∼2.8μB/Fe. No interfacial magnetization is observed at the (100)-BFO/LSMO interface when LSMO is an antiferromagnet. In contrast to (100)-oriented superlattices, no induced moment is observed in (111)-BFO layers. Our results suggest the interfacial structural reconstruction may not be a sufficient condition for the enhanced net moment in BFO layer. Instead, spin canting induced by interfacial exchange coupling is proposed in the (100)- but not in the (111)-BFO, leading to the large net magnetization at the (100)-oriented interface. This work further demonstrates the importance of exchange coupling across heterointerfaces for spin canting in nominally antiferromagnets, providing a pathway to control the magnetic properties of artificial oxide heterostructures.
Original language | English |
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Article number | 114404 |
Journal | Physical Review Materials |
Volume | 2 |
Issue number | 11 |
DOIs | |
State | Published - Nov 13 2018 |
Funding
This work was conducted at the Spallation Neutron Source of Oak Ridge National Laboratory, which is a US Department of Energy (DOE), Office of Science User Facility. A part of work was sponsored by US DOE, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division (sample synthesis, physical property characterization, and theory inputs). M.A.R. acknowledges the use of facilities within the Eyring Materials Center at Arizona State University (TEM imaging). X.S. acknowledges the support from the Center for Nanophase Materials Sciences (CNMS), which is a DOE Office of Science User Facility (fruitful TEM result discussions).