High entropy oxide systems based on rare earth elements

Abstract

In this paper we synthesized high entropy oxide system (Sc0.2Ce0.2Pr0.2Gd0.2Ho0.2)2O3±δ by precipitation of hydroxides from REE nitrates aqueous solutions and annealing the mixture at 800 °C. It is possible to obtain the various forms of simple and complex composition based on the rare earth oxides, including oxides in the form of nanosized powders. The main idea of obtaining HEOS comes from the field of high-entropy alloys. The interconnection between configurational entropy and mixing enthalpy is a key factor for determining phase transformations. The phase composition, structure, and surface morphology of the obtained powders were investigated by scanning electron microscopy and X-ray phase analysis methods.

High-entropy rare earth materials: synthesis, application and outlook

“…Amelichkin and co-workers synthesized an HE oxide system, (Sc 0.2 Ce 0.2 Pr 0.2 Gd 0.2 Ho 0.2 ) 2 O 3AEd , through the precipitation of hydroxides from aqueous solutions of RE element nitrates, followed by annealing the mixture at 800 1C. 131 Inspired by the concept of HE alloys, the relationship between configurational entropy and mixing enthalpy was explored to determine phase transformations. This approach, as an extension of the new method of synthesizing HE oxides, allows for the production of various forms of simple and complex compositions.…”

Structural and Optical Properties of High Entropy (La,Lu,Y,Gd,Ce)AlO3 Perovskite Thin Films

“…[ 34 ] There is an immense amount of high entropy oxide materials (200+) that may show interesting optical properties. [ 35 , 36 , 37 , 38 , 39 , 40 , 41 ] For example, the stabilization of a high entropy sesquioxide ceramic phosphor has been shown to exhibit multi‐wavelength emission with a high degree of optical transparency in the visible region. [ 42 ] On the other hand, Ce‐doped RE‐based oxides have been observed to have narrow band gaps with absorption over the entire visible spectra.…”