Spinel-type high-entropy (Co0.2Mn0.2Fe0.2Zn0.2Ti0.2)3O4 oxides constructed from disordered cations and oxygen vacancies

Here, an entropy engineering approach was employed to design the high-entropy (Co0.2Mn0.2Fe0.2Zn0.2Ti0.2)(3)O-4 solid-solution ceramics under different sintering temperatures (925-1025 degrees C). The crystal structure, thermal behavior, morphology, and chemical state of the synthesized high-entropy oxides (HEOs) were carefully evaluated. Results reveal that the single spinel phase (Fd 3 m) is retained over the entire sintering temperature range and no clustering or segregation of elements, indicating superior structural stability and the formation of a pure entropy-stabilized phase. It derives from the disordered occupation of the multivalent cations in the two sublattices of spinel and the generation of oxygen vacancies. The successful preparation of such a new class of spinel-type high-entropy ceramics will bring an innovative perspective to the design of advanced materials and provide ideas for further full exploration of their potentials in catalytic, electronic, and energy applications. (C) 2021 Elsevier B.V. All rights reserved.