Orbital Hybridization Induced by Double‐Anion Coordination to Enhance Room‐Temperature Ferromagnetic Response

The oxygen introduction is expected to enable manipulation of material properties, however, the coordination mechanism between oxygen and other nonmetal dopants remains inadequate. Herein, the oxygen introduction into cobalt selenides has been achieved through annealing in a controlled gas environment to disclose the anion defects formation process. Superconducting quantum interference device (SQUID) measurements indicate that the cobalt selenides annealed exhibit significantly enhanced room‐temperature ferromagnetism. Calculations reveal that the magnetic improvement is mainly attributed to orbital hybridization induced by double‐anion coordination (selenium and oxygen). This work can provide new insight into the role of oxygen incorporation in magnetic structure transformation.