Induced Ferromagnetism in Epitaxial Uranium Dioxide Thin Films
- Center for Integrated Nanotechnologies (CINT) Los Alamos National Laboratory Los Alamos NM 87545 USA, Glenn T. Seaborg Institute Los Alamos National Laboratory Los Alamos NM 87545 USA
- Center for Integrated Nanotechnologies (CINT) Los Alamos National Laboratory Los Alamos NM 87545 USA
- Neutron Scattering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA, Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
- Materials Science and Technology Division Los Alamos National Laboratory Los Alamos NM 87545 USA
- Department of Materials Design and Innovation University at Buffalo The State University of New York Buffalo NY 14260 USA
- National High Magnetic Field Laboratory (NHMFL) Los Alamos National Laboratory Los Alamos NM 87545 USA
- Neutron Scattering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA
- Neutron Scattering Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA, Materials Science and Technology Division Oak Ridge National Laboratory Oak Ridge TN 37831 USA, Department of Physics and Astronomy University of Tennessee Knoxville TN 37996 USA
- Glenn T. Seaborg Institute Los Alamos National Laboratory Los Alamos NM 87545 USA
Abstract Actinide materials have various applications that range from nuclear energy to quantum computing. Most current efforts have focused on bulk actinide materials. Tuning functional properties by using strain engineering in epitaxial thin films is largely lacking. Using uranium dioxide (UO 2 ) as a model system, in this work, the authors explore strain engineering in actinide epitaxial thin films and investigate the origin of induced ferromagnetism in an antiferromagnet UO 2 . It is found that UO 2+ x thin films are hypostoichiometric ( x <0) with in‐plane tensile strain, while they are hyperstoichiometric ( x >0) with in‐plane compressive strain. Different from strain engineering in non‐actinide oxide thin films, the epitaxial strain in UO 2 is accommodated by point defects such as vacancies and interstitials due to the low formation energy. Both epitaxial strain and strain relaxation induced point defects such as oxygen/uranium vacancies and oxygen/uranium interstitials can distort magnetic structure and result in magnetic moments. This work reveals the correlation among strain, point defects and ferromagnetism in strain engineered UO 2+ x thin films and the results offer new opportunities to understand the influence of coupled order parameters on the emergent properties of many other actinide thin films.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program; National Science Foundation (NSF); USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division; USDOE Office of Science (SC), Basic Energy Sciences (BES). Chemical Sciences, Geosciences & Biosciences Division
- Grant/Contract Number:
- 89233218CNA000001; 20220485MFR; 20210640ECR; DMR 1157490; DMR 1644779; AC52-06NA25396
- OSTI ID:
- 1891546
- Alternate ID(s):
- OSTI ID: 1897434; OSTI ID: 1899730
- Report Number(s):
- LA-UR-22-21918; 2203473
- Journal Information:
- Advanced Science, Journal Name: Advanced Science Vol. 9 Journal Issue: 33; ISSN 2198-3844
- Publisher:
- Wiley Blackwell (John Wiley & Sons)Copyright Statement
- Country of Publication:
- Germany
- Language:
- English
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