High entropy oxides: a new playground for functional materials development
le mercredi 23 mars à 11h00 à l’auditorium.
Since their first report by Rost et al. in 2015 , Entropy Stabilized Oxides and High Entropy Oxides (HEOx) have become a hot topic in the field of functional oxides, with many papers devoted to the synthesis of new compositions and structures and to the study of various functional properties.
Similarly to high entropy alloys, HEOx are obtained by mixing at least five binary oxide precursors, heating them above a critical temperature at which the entropy of configuration becomes the main component of the Gibbs free energy, and quenching them to room temperature. Following this process, metastable single phase solid solutions are obtained, with a random distribution of the cations on one (or several) cationic sublattice. To date, many compositions have been obtained with different crystal structures, and some of them exhibit promising functional properties, among other: superionic Li conductivity or fast ionic conductivity, colossal dielectric constants, photocatalytic properties, unexpected magnetic ordering, …
In this talk, we will give an overview of this emerging field, and discuss the perspectives it opens for the functional oxides’ community.
 C.M. Rost et al., Entropy-stabilized oxides, Nature communications 6, 8485 (2015)