Characterization of lanthanide high entropy oxides using transmission electron microscopy

Abstract

• Difficulty in figuring out lanthanide composition from EDS Spectra from HEO samples. • Confirmation on the formation of single-phase in five lanthanide-based HEO samples. • The application of SAED and EELS for the identification of composition isotropy. • Determination of oxidation states of lanthanides elements in HEO at nanoscale. Lanthanide based high entropy oxide (HEO) catalyst supports are promising nanomaterials for catalysis reactions. The interplay among structural, elemental, and chemical forces results in the formation of a specific phase for synthesized HEOs. The determination of structure and chemistry of the phase is a challenge due to the presence of high number of elements. We apply different modalities of transmission electron microscopy (TEM) technique to determine both structure and oxidation states of the HEO phase in samples that are synthesized with the coprecipitation of five lanthanide metals.