Abstract
We demonstrate an unexpected substrate dependence of the magnetic properties of complex oxide thin film membranes. While the tunable magnetism of complex oxides is attractive for many applications, device integration has long been limited by the strict substrate requirements necessary for high-quality film growth. Recently, water-soluble sacrificial layers have been used to separate oxide thin films from the substrate after growth, decoupling the structural and chemical degrees of freedom at the interface. This approach is hoped to enable integration with previously incompatible material platforms, but interface studies of transferred films remain limited. In this work, we use polarized neutron reflectometry and secondary ion mass spectroscopy to provide a detailed understanding of depth-dependent chemistry and magnetization of LaMnO3 membranes. We find that the final substrate plays a key role in either incorporating or excluding hydrogen species at the surfaces of transferred LaMnO3 thin films, modifying the magnetism in these interfacial regions. Despite elimination of the epitaxial relationship, the choice of substrate influences the magnetism within the transferred membranes to an unexpected degree, with important implications for integration into existing silicon-based technologies.
| Original language | English |
|---|---|
| Journal | Journal of Physical Chemistry C |
| DOIs | |
| State | Accepted/In press - 2024 |
Funding
This work was financially supported in part by the National Key R&D Program of China (No. 2022YFA1403000), the National Natural Science Foundation of China (Nos. 52072244 and 12104305), the Science and Technology Commission of Shanghai Municipality (No. 21JC1405000), and the Double First-Class Initiative Fund of ShanghaiTech University. This research used resources at the Spallation Neutron Source, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Access to CANDOR was provided by the Center for High Resolution Neutron Scattering, a partnership between the National Institute of Standards and Technology (NIST) and the National Science Foundation under Agreement No. DMR-2010792. This research was performed in part at the NIST Center for Nanoscale Science and Technology and used resources from the Analytical Instrumentation Center (#SPST-AIC10112914) and the Centre for High-resolution Electron Microscopy (C\u210FEM) (EM02161943) at ShanghaiTech University. This research was performed while the author P.P.B. held an NRC Research Associateship award at NIST. We thank Elizabeth Kelley (NCNR) for assistance with chemical processing of films between PNR measurements. Certain commercial equipment, instruments, software, or materials are identified in this paper in order to specify the experimental procedure adequately. Such identifications are not intended to imply recommendation or endorsement by NIST nor it is intended to imply that the materials or equipment identified are necessarily the best available for the purpose.
| Funders | Funder number |
|---|---|
| NIST Center for Neutron Research | |
| Double First-Class Initiative Fund of ShanghaiTech University | |
| Oak Ridge National Laboratory | |
| ShanghaiTech University | |
| Office of Science | |
| Elizabeth Kelley | |
| National Key Research and Development Program of China | 2022YFA1403000 |
| National Natural Science Foundation of China | 52072244, 12104305 |
| National Institute of Standards and Technology | AIC10112914, EM02161943 |
| National Science Foundation | DMR-2010792 |
| Science and Technology Commission of Shanghai Municipality | 21JC1405000 |