Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe2 Semiconductor with an Out-of-Plane Anisotropy

摘要

The intrinsically nonmagnetic feature of van der Waals (vdW) layered transition-metal dichalcogenide (TMDC) semiconductors limits the spintronic applications of these semiconductors. In this paper, we demonstrate a facile Te flux strategy to induce intrinsic ferromagnetism in the vdW layered 2H-MoTe_(2) semiconductor by magnetic chromium (Cr) doping. The Curie temperature (T _(c)) and saturation magnetization (M _(s)) can be well tuned by adjusting the Cr doping concentration. A notable T _(c) up to 275 K can be achieved for the vdW layered Cr-doped 2H-MoTe_(2) bulk crystals, which is much higher than that of recently reported van der Waals ferromagnetic semiconductors (T _(c) is mostly less than 70 K), in contrast to the diamagnetic feature of the pristine MoTe_(2). Meanwhile, the highest M _(s) of the vdW layered Cr-doped 2H-MoTe_(2) bulk crystals can reach 4.78 emu g~(–1), which is stronger than most values reported for magnetic-element-doped van der Waals materials. In addition, all of the as-grown semiconducting Cr-doped 2H-MoTe_(2) (Cr-2H-MoTe_(2)) single crystals display a large magnetic anisotropy with an out-of-plane easy axis of magnetization. The observed ferromagnetism in the Cr-2H-MoTe_(2) has intrinsic characteristics, which can be mainly attributed to the spin polarization caused by Cr doping as confirmed by the density functional theory (DFT) calculations. Our approach offers an avenue to tune the ferromagnetism in the vdW layered semiconductor and explore its diverse spintronic and magnetoelectric applications.