Abstract
About this talk
High-entropy spinel oxides provide an excellent platform for investigating entropy-stabilized correlated systems with strong configurational disorder. In this work, we systematically studied the temperature evolution of the structural and magnetic properties of Cr-based high-entropy spinels with compositions (Mn0.2Co0.2Ni0.2Cu0.2Zn0.2)Cr2O4 and (Mg0.2Co0.2Ni0.2Cu0.2Zn0.2)Cr2O4. Our results reveal that both systems crystallize in a cubic structure with the space group Fd -3m at room temperature. Each system undergoes antiferromagnetic ordering below the Ne´el temperatures TN = 49 K and 35 K, respectively. Low-temperature neutron diffraction measurements confirm the long-range magnetic ordering in the Mn-containing sample. Both systems exhibit a structural phase transition from the cubic Fd -3m to the orthorhombic Fddd symmetry at approximately 55 K and 85 K, respectively. Notably, despite the significant chemical disorder at the A site, both systems undergo transitions analogous to those observed in low entropy spinel systems. This behavior suggests that a high configurational entropy may promote global structural stabilization despite local chemical disorder, thereby preserving long-range orderings and the characteristic symmetry-breaking transitions of the pristine spinel systems.
Speaker
About the speaker
