From Chemical Complexity to Tunable Magnetic Ordering in Highly Disordered High-Entropy Spinel Oxides
Year: 2026
Type: preprint
Abstract: High-entropy stabilization chemistry is redefining materials design by transforming configurational disorder, arising from the deliberate incorporation of multiple principal cations, into a thermodynamic advantage that promotes phase stability and enables emergent functionalities. In this work, we investigate the evolution of magnetic ordering in spinel-type high entropy oxides by systematically varying the cation composition of the B site within a fixed high-entropy A-site matrix, (Ni$_{0.2}$Mg$_{0.2}$Co$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$)B$_2$O$_4$. Upon introducing multicomponent B-site configurations, we uncover a strikingly linear dependence of the magnetic transition temperature (T$_C$) on the T$_C$s of the corresponding single B-site high-entropy systems. Remarkably, this trend persists even in highly complex (Ni$_{0.2}$Mg$_{0.2}$Co$_{0.2}$Cu$_{0.2}$Zn$_{0.2}$)(Cr$_{0.2}$Mn$_{0.2}$Fe$_{0.2}$Ga$_{0.2}$X$_{0.2}$)$_2$O$_4$, X = Al and Ti. Despite the material's extremely high degree of disorder, absence of a dominant magnetic ion or a straightforward superexchange pathway, detailed magnetization measurements, low-temperature X-ray magnetic circular dichroism, and neutron powder diffraction studies reveal robust long-range ferrimagnetic ordering. These results reveal an emergent predictability in ferrimagnetic high-entropy spinel oxides, where, despite extreme configurational disorder and competing interactions, robust ferrimagnetic order can arise from, rather than be hindered by, extreme configurational disorder. This establishes a pathway for predictively tuning magnetic transition temperatures in high-entropy oxides beyond conventional ordered systems.
Source: arXiv (Cornell University)
Institutions: Thapar Institute of Engineering & Technology, Freie Universität Berlin, Helmholtz-Zentrum Berlin für Materialien und Energie, UGC-DAE Consortium for Scientific Research, Mumbai Centre, Bhabha Atomic Research Centre, Bhabha Atomic Research Center Hospital, UGC DAE Consortium for Scientific Research, Centre National de la Recherche Scientifique, École Nationale Supérieure d'Ingénieurs de Caen, Normandie Université, Laboratoire de Cristallographie et Sciences des Matériaux, Université de Caen Normandie
Language: English
Topic: High Entropy Alloys Studies
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
Award: G114513580
OpenAlex ID: W7214950593