Effect of cooling regime on structure of entropy-stabilized oxides (MgNiCoCuZn)O

The effect of various cooling regimes on the evolution of the crystal structure of entropy- stabilized oxides (MgNiCoCuZn)O has been studied using a high-resolution time-of-flight neutron Fourier diffractometer. It has been established that cooling in a furnace at a rate of 1, 2, and 5 K/min leads not only to the segragation of a part of copper oxide into a separate phase, but also to nanostructuring of both the main matrix and CuO. The characteristic sizes of the formed nanoparticles are determined. It is shown that the expected rhombohedral or tetragonal distortions due to the possible Jahn-Teller effect are not observed in these samples.