Figure 13.

Quality versus magnetism in 2D TMDs. (a) Temperature dependent M versus H loops for a MBE grown, 30% V-doped 2D ${\text{WSe}}_2$ on sapphire showing the absence of any ferromagnetism at 100 K. (b) As-grown V-doped 2D ${\text{WSe}}_2$ sample grown on ${\text{SiO}}_2/\text{Si}$ was intentionally annealed to create Se vacancies. (c) Magnetic force microscopy (MFM) phase images measured at 120 K for as-grown and 500 °C annealed 0.5% V-doped ${\text{WSe}}_2$ are compared: The as-grown ${\text{WSe}}_2$ exhibits a negligible MFM phase contrast with respect to the ${\text{SiO}}_2/\text{Si}$. In contrast, the annealed ${\text{WSe}}_2$ exhibits a distinct magnetic domain contrast, confirming ferromagnetism in the annealed sample. Panels (b) and (c) were adapted and modified with permission from ref 256. Copyright 2022 John Wiley & Sons, Inc.