Epitaxial entropy-stabilized oxides: Growth of chemically diverse phases via kinetic bombardment

This paper explores thin films of the entropy-stabilized oxide (ESO) composition Mg_xNi_xCo_xCu_xZn_xSc_xO (x ~ 0.167) grown by laser ablation in incremental gas pressures and O2/Ar ratios to modulate particle kinetic energy and plume reactivity. Low pressures supporting high kinetic energy adatoms favor the kinetic stabilization of a single rocksalt phase, while high pressures (low kinetic energy adatoms) result in phase separation. The pressure threshold for phase separation is a function of O₂/Ar ratio. These findings suggest large kinetic energies facilitate the assembly and quench of metastable ESO phases that may require immoderate physical or chemical conditions to synthesize using near-equilibrium techniques.