Magnetic electrides: anion-engineered spin-topology phenomena

Electrides constitute a unique class of ionic compounds where electrons localized in lattice cavities/channels serve as discrete anions rather than being bound to atoms. Recent years have witnessed a surge of interest in magnetic electrides. This review systematically elaborates their discovery strategies, design principles, unique magnetic origin, electronic structures, exotic properties, and cross-domain applications. Distinct from conventional magnetic systems, their magnetic ordering originates from either spin-polarized interstitial anionic electrons (IAEs) or orbital electron moments, enabling room-temperature ferromagnetism, spin-Peierls transitions and so on. Property modulation reveals emergent topological states and quantum behaviors in selected systems, with cutting-edge research focusing on dynamic control of magneto-topological phase transitions via external regulations. Moreover, applications demonstrate transformative potential for quantum devices, sustainable energy, and catalysis—particularly through IAE-enabled electron transfer mechanisms that substantially enhance spintronic efficiency, ion storage capacity, and catalytic performance.