Abstract
Ultrathin epitaxial films of ferromagnetic insulators (FMIs) with Curie temperatures near room temperature are critically needed for use in dissipationless quantum computation and spintronic devices. However, such materials are extremely rare. Here, a room-temperature FMI is achieved in ultrathin La0.9Ba0.1MnO3 films grown on SrTiO3 substrates via an interface proximity effect. Detailed scanning transmission electron microscopy images clearly demonstrate that MnO6 octahedral rotations in La0.9Ba0.1MnO3 close to the interface are strongly suppressed. As determined from in situ X-ray photoemission spectroscopy, O K-edge X-ray absorption spectroscopy, and density functional theory, the realization of the FMI state arises from a reduction of Mn eg bandwidth caused by the quenched MnO6 octahedral rotations. The emerging FMI state in La0.9Ba0.1MnO3 together with necessary coherent interface achieved with the perovskite substrate gives very high potential for future high performance electronic devices.
| Original language | English |
|---|---|
| Article number | 1901606 |
| Journal | Advanced Science |
| Volume | 7 |
| Issue number | 1 |
| DOIs | |
| State | Published - Jan 1 2020 |
Funding
W.-W.L., B.Z., and Q.H. contributed equally to this work. W.-W.L. and J.L.M.-D. acknowledge support from EPSRC grant EP/L011700/1, EP/N004272/1, and the Isaac Newton Trust (Minute 13.38(k)). B.Z. acknowledges support from the China Scholarship Council and the Cambridge Commonwealth, European and International Trust. K.H.L.Z. is grateful for funding support by the Thousand Youth Talents Program of China. Q.H. acknowledges the Research fellowship from Cardiff University. A.B. acknowledges support from the Materials Science and Engineering Division of the U.S. DOE Office of Science, Basic Energy Sciences. S.C. acknowledges Diamond Light Source for the provision of beamtime under SI17284. Sandia National Laboratory is a multiprogram laboratory managed and operated by the National Technology and Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International, Inc., for the U.S. DOE's National Nuclear Security Administration under contract DE-NA0003525. Z.Q. and H.W. acknowledge the support from the U.S. National Science Foundation (DMR-1809520) for the TEM effort at Purdue University. The work at Los Alamos National Laboratory was supported by the NNSA's Laboratory Directed Research and Development Program and was performed, in part, at the Center for Integrated Nanotechnologies, an Office of Science User Facility operated for the U.S. DOE Office of Science. Los Alamos National Laboratory, an affirmative action equal opportunity employer, is managed by Triad National Security, LLC for the U.S DOE's NNSA, under contract 89233218CNA000001. Note: Ref. [56] was corrected on 8 January 2020 after original online publication.
| Funders | Funder number |
|---|---|
| DOE Office of Science | |
| Materials Science and Engineering Division | |
| NNSA's | |
| Sandia National Laboratory | |
| Thousand Youth Talents Program of China | |
| U.S. National Science Foundation | DMR-1809520 |
| National Science Foundation | |
| U.S. Department of Energy | |
| Directorate for Mathematical and Physical Sciences | 1809520 |
| Basic Energy Sciences | SI17284 |
| National Nuclear Security Administration | DE-NA0003525 |
| Purdue University | |
| Los Alamos National Laboratory | 89233218CNA000001 |
| Engineering and Physical Sciences Research Council | EP/L011700/1, EP/N004272/1 |
| Cardiff University | |
| China Scholarship Council | |
| Isaac Newton Trust |
Keywords
- ABO perovskite oxides
- ferromagnetic insulators
- interface engineering
- manganite thin films
- octahedral proximity effect