Synthesis and Property Characterization of Rare-Earth High-Entropy Oxides with Pyrochlore-Type Structures

In the search for novel materials with advanced physical properties, the concept of adding configurational entropy onto a single atomic site is known to provide new avenues toward material discovery. In the case of high entropy oxides (HEOs), the ability to “tune” a material’s properties by having multiple cations on single or multiple sites allows for greater opportunity to design materials for specific applications. The work presented here explores the synthesis of new multicomponent (high entropy) oxides, followed by a detailed characterization using several techniques. We have successfully synthesized multiple single-phase polycrystalline rare-earth high entropy oxides and grown large, bulk single crystals with the titanate pyrochlore composition using the floating zone technique. Characterization involving mechanical stiffness, thermal expansion, and irradiation amorphization resistance is presented, allowing for a detailed investigation of these new complex oxides and their potential applications.