Two‐dimensional air‐stable non‐layered ferrimagnetic FeCr2S4 crystals synthesized via chemical vapor deposition

Abstract The discovery of intrinsic two‐dimensional (2D) magnetic materials has opened up new opportunities for exploring magnetic properties at atomic layer thicknesses, presenting potential applications in spintronic devices. Here we have synthesized a new 2D ferrimagnetic crystal of non‐layered FeCr 2 S 4 with high phase purity using chemical vapor deposition. The obtained 2D FeCr 2 S 4 exhibited perpendicular magnetic anisotropy, as evidenced by the out‐of‐plane/in‐plane Hall effect and anisotropic magnetoresistance. Theoretical calculations further elucidated that the observed magnetic anisotropy can be attributed to its surface termination structure. By combining temperature‐dependent magneto‐transport and polarized Raman spectroscopy characterizations, we also discovered that both the measured Curie temperature and the critical temperature at which a low energy magnon peak disappeared remained constant, regardless of its thickness. Magnetic force microscopy measurements showed the flipping process of magnetic domains. The exceptional air‐stability of the 2D FeCr 2 S 4 was also confirmed via Raman spectroscopy and Hall hysteresis loops. The robust anisotropic ferrimagnetism, the thickness‐independent of Curie temperature, coupled with excellent air‐stability, make 2D FeCr 2 S 4 crystals highly attractive for future spintronic devices. This article is protected by copyright. All rights reserved