Probing Ferrimagnetic Semiconductor with Enhanced Negative Magnetoresistance: 2D Chromium Sulfide

Magnetic 2D materials have emerged as a great interest in spintronics due to atomic thickness scaling, low energy switching, and ease in the manipulation of spins. This report demonstrates a facile, bottom‐up, chemical vapor deposition approach for non‐van der Waals (non‐vdWs), 2D chromium (III) sulfide (Cr 2 S 3 ) with c ‐axis orientation, out‐of‐plane magnetic anisotropy (easy axis), and ferrimagnetic ordering. Importantly, the anisotropic magnetic saturation and resistivity of 10.23 mΩ cm reveal a narrow bandgap ferrimagnetism in Cr 2 S 3 (∆ E Activation  ≈ 22 meV and E g  ≈ 40 meV). The prototype lateral spin‐channel Al/Cr 2 S 3 /Al devices exhibit a negative magnetoresistance of ≈25% and ≈15% at 100 K (below Néel temperature) for few‐layer (≈8 nm) and thin‐film (≈50 nm) device structures, respectively, owing to itinerant ferrimagnetism of Cr 2 S 3 . The magnetic field‐induced spin polaron formations are quite resilient and enhance the field‐dependent carrier conduction, making it greatly useful for negative magnetoresistance operation. These prototype Al/Cr 2 S 3 /Al structures have demonstrated a low power (≈2 µW for 8 µm channel at 10 µA current) operation with a negative field‐dependent resistance coefficient ( r M ) of ≈−5 × 10 −4  Oe −1 . The computed r M magnitude is tenfold higher than the bulk Cr 2 S 3 . This study identifies the potential of non‐vdW Cr 2 S 3 toward new and robust 2D‐based spintronic applications.