Half-Metallic Antiferromagnetic 2D Nonlayered Cr₂Se₃ Nanosheets

Half-metallic magnetism, characterized by metallic behavior in one spin direction and semiconducting or insulating behavior in the opposite spin direction, is an intriguing and highly useful physical property for advanced spintronics because it allows for the complete realization of 100% spin-polarized current. Particularly, half-metallic antiferromagnetism is recognized as an excellent candidate for the development of highly efficient spintronic devices due to its zero net magnetic moment combined with 100% spin polarization, which results in lower energy losses and eliminates stray magnetic fields compared to half-metallic ferromagnets. However, the synthesis and characterization of half-metallic antiferromagnets have not been reported until now as the theoretically proposed materials require a delicate and challenging approach to fabricate such complex compounds. Here, we propose Cr₂Se₃ as the experimentally synthesizable half-metallic antiferromagnet. Our experimental and theoretical studies─including magnetic property measurements, spin-resolved density functional theory calculations, and tunneling magnetoresistance experiments─confirm its half-metallic antiferromagnetic behavior. We demonstrate that the 2D nonlayered Cr₂Se₃ synthesized via chemical vapor deposition offers an ideal platform for innovative spintronics applications and fundamental research into half-metallic antiferromagnets.