Oxygen Plasma‐Induced Magnetic Modulation and Air Stability Enhancement of 2D 1T‐CrTe ₂

Two‐dimensional (2D) magnets hold promise for spintronics but still face challenges regarding limited magnetic tunability and air stability. Here, we demonstrate an effective oxygen plasma treatment strategy that simultaneously modulates magnetism and enhances the air stability of 1T‐CrTe 2 films. Microstructural characterizations reveal a depth‐dependent progressive oxygen induced reconstruction process, in which oxygen substitution induces local Cr–Te–O structural rearrangements that are more pronounced near the surface and gradually extend toward the inner layers with increasing treatment duration. Theoretical calculations combined with magnetic measurements suggest that the effective oxidation level regulates interlayer magnetic coupling, leading to an evolution from a FiM‐related step‐like magnetic transition behavior to a FM‐dominated magnetic response. Significantly, the oxygen‐doped 1T‐CrTe 2 exhibits robust environmental stability, retaining room‐temperature magnetism even after long‐term ambient exposure. This work presents a dual‐purpose approach for engineering robust, tunable 2D materials for future spintronic applications.