Disorder Driven Relaxor Ferrorelectrics—A Computational Design Strategy

High entropy, multi-component metal alloys, have superior mechanical properties and high radiation tolerances; which are, in part, driven by configurational entropy. Recently, an oxide analogue comprised of MgO, CoO, NiO, CuO and ZnO was synthesized; exhibiting a truly entropy-stabilized, reversible phase transition from a multiphase material to a single rock salt-ordered phase above 850-900°C. This entropy-driven stabilization may engender many unique properties, such as high melting temperatures, radiation resistance and other anomalous responses. Here, we discuss a design strategy for the prediction of synthesizable disordered oxides. Our effort employs first principles studies of 2-component oxides to develop design rules based on the relationship between pairwise enthalpies of formation, △H, and configurational entropy of the disordered material. A similar chemical identity-to-△H map was previously explored using the class of high entropy alloys, where the stability of multicomponent metal alloys was correlated to the enthalpy of mixing of binary and ternary compounds. Here, the focus will be on the exploration and discovery of synthesizable entropy-stabilized Ba-based perovskites that rely on configurational disorder to foster relaxor ferroelectric behavior.<br/>This work was supported by the U.S. D.O.E., Office of Science, BES, MSED using resources at NERSC and OLCF.