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

Abstract

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-MoTe2 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-MoTe2 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 MoTe2. Meanwhile, the highest M s of the vdW layered Cr-doped 2H-MoTe2 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-MoTe2 (Cr-2H-MoTe2) single crystals display a large magnetic anisotropy with an out-of-plane easy axis of magnetization. The observed ferromagnetism in the Cr-2H-MoTe2 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.

Synthesis of Group VIII Magnetic Transition-Metal-Doped Monolayer MoSe2

“…20,21 Li et al reported that Fe-doped SnS 2 exhibited ferromagnetic behavior with a Curie temperature (T C ) of 31 K. 22 Chang et al reported that the Cr-doped T d -WTe 2 displayed a maximum saturation magnetization of 4.20 emu g −1 with a T C of 283 K, and the Cr-doped 2H-MoTe 2 displayed a large out-of-plane magnetic anisotropy. 23,24 Nevertheless, the approaches obtaining magnetic-element-doped TMD samples by chemical vapor transport or flux methods followed by mechanical exfoliation still have some inevitable drawbacks including low doping concentration, poor yield, and low scalability. efficient method to obtain magnetic-element-doped TMDs.…”

Liquid-precursor-intermediated synthesis of atomically thin transition metal dichalcogenides

“…Materials with both ferromagnetic and semiconducting properties are called dilute magnetic semiconductors, which have great potential applications in spintronics and magnetoelectrics. 80,81 The doping of magnetic atoms such as Fe, Co, Ni, Mn, and V will produce ferromagnetism in non-ferromagnetic 2D TMDs. [82][83][84] Thus, the LPI-CVD method has become one of the most effective methods for the controllable synthesis of substitutional magnetic transition metal-doped atomically thin TMDs.…”

Single crystal growth and intrinsic anomalous Hall effect of Cr2.70Se0.60Te3.40 ferromagnetic crystals

“…For example, Cr 2 Ge 2 Te 6 , CrI 3 , Fe 3 GaTe 2 , Cr x Ga 1− x Te, Cr–WTe 2 , Cr–MoTe 2 , Cr–NiTe 2 and Ta–MoTe 2 thin flakes exhibit low-temperature or near room temperature layer-dependent ferromagnetism with out-of-plane anisotropy. 3,16–23…”