Abstract
High-entropy oxides (HEOs) have aroused growing interest due to fundamental questions relating to their structure formation, phase stability, and the interplay between configurational disorder and physical and chemical properties. Introducing Fe(II) and Mn(II) into a rocksalt HEO is considered challenging, as theoretical analysis suggests that they are unstable in this structure under ambient conditions. Here, we develop a bottom-up method for synthesizing Mn- and Fe-containing rocksalt HEO (FeO-HEO). We present a comprehensive investigation of its crystal structure and the random cation-site occupancy. We show the improved structural robustness of this FeO-HEO and verify the viability of an oxygen sublattice as a buffer layer. Compositional analysis reveals the valence and spin state of the iron species. We further report the antiferromagnetic order of this FeO-HEO below the transition temperature ~218 K and predict the conditions of phase stability of Mn- and Fe-containing HEOs. Our results provide fresh insights into the design and property tailoring of emerging classes of HEOs.
Original language | English |
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Article number | eadi8809 eadi8809 |
Journal | Science Advances |
Volume | 9 |
Issue number | 38 |
DOIs | |
State | Published - 2023 |
Funding
Assistance by M. Kirkham and A. Manjon-Sanz for NPD at POWGEN is gratefully acknowledged. This research used resources at the SNS, a DOE Office of Science User Facilities operated by the Oak Ridge National Laboratory. Part of this research was conducted on the XAS Beamline, Australian Synchrotron, part of ANSTO. This research used Echidna at the Australian Centre for Neutron Scattering. This work was financially supported by the Science for Technological Innovation (SfTI) Challenge program grant no. UOAX1604 (to P.C. and Y.P.). U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under contract no. DE-AC05-00OR22725 (to R.P.H., M.E.M.., D.M., J.Y., and V.R.C.). We are grateful for beamtime at the Australian Synchrotron ID 17907 (to Y.P. and P.C.) and the Australian Centre for Neutron Scattering MI13169 (to Y.P. and P.C.).
Funders | Funder number |
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Science for Technological Innovation | UOAX1604 |
U.S. Department of Energy | |
Office of Science | |
Basic Energy Sciences | |
Oak Ridge National Laboratory | |
Division of Materials Sciences and Engineering | DE-AC05-00OR22725, 17907, MI13169 |