Synthesis, densification, and cation inversion in high entropy (Co,Cu,Mg,Ni,Zn)Al₂O₄ spinel

The synthesis, densification behavior, and crystallographic site occupancy were investigated for four different spinel-based ceramics, including a high-entropy spinel (Co0.2Cu0.2Mg0.2Ni0.2 Zn0.2)Al2O4. Each composition was reacted to form single phase, but analysis of X-ray diffraction patterns revealed differences in cation with the being nearly fully normal. Densification behavior showed that dense ceramics could be produced by hot pressing at temperatures as low 1375°C all compositions. Vickers’ hardness values least 10 GPa cations present appear have stabilizing effect led normal compared full inversion nickel aluminate spinel. This is first report compares conventional ceramics.