| Abstract Scope |
High-entropy oxides are solid solutions with more than five elements occupying one or more sites. The oxygen anions buffer the cations which yields more flexibility than in high-entropy alloys. These materials might find applications for thermal barriers, batteries, or catalysis. Mixing enthalpy and configurational entropy are key in determining phase stability. In the bulk, only few 3d-metal-based rocksalt oxides have been synthesized; we investigated (Mg,Co,Ni,Cu,Zn)O[1] and (Mg,Mn,Fe,Co,Ni)O[2], the latter requiring precise control of oxygen partial pressure during synthesis. Neutron diffraction and spectroscopy and muon spin rotation[3] reveal magnetic order and magnetic entropy.
Manuscript coauthors are gratefully acknowledged. Work supported by DOE Office of Basic Energy Sciences, Materials Sciences and Engineering Division. This research used resources at the Spallation Neutron Source and High Flux Isotope Reactor, facilities supported by DOE, BES, Scientific User Facilities Division, and at TRIUMF, Vancouver, Canada.
1. doi.org/10.1021/acs.chemmater.9b00624
2. doi.org/10.1126/sciadv.adi880
3. doi.org/10.1103/PhysRevMaterials.4.074405 |