Room-temperature ferromagnetism in monolayer WSe2 semiconductor via vanadium dopant

TL;DR

This study demonstrates room-temperature ferromagnetism with long-range order in V-doped WSe2 monolayers, modulated by gating, highlighting potential for 2D spintronic applications.

Contribution

First report of room-temperature ferromagnetic order in V-doped WSe2 monolayers with gate control, synthesized via chemical vapor deposition.

Findings

Ferromagnetic domains observed up to 360K.

High on/off current ratio maintained at 0.1% V-doping.

Long-range ferromagnetic order likely due to RKKY interaction.

Abstract

Diluted magnetic semiconductors including Mn-doped GaAs are attractive for gate-controlled spintronics but Curie transition at room temperature with long-range ferromagnetic order is still debatable to date. Here, we report the room-temperature ferromagnetic domains with long-range order in semiconducting V-doped WSe2 monolayer synthesized by chemical vapor deposition. Ferromagnetic order is manifested using magnetic force microscopy up to 360K, while retaining high on/off current ratio of ~105 at 0.1% V-doping concentration. The V-substitution to W sites keep a V-V separation distance of 5 nm without V-V aggregation, scrutinized by high-resolution scanning transmission-electron microscopy, which implies the possibility of the Ruderman-Kittel-Kasuya-Yoshida interaction (or Zener model) by establishing the long-range ferromagnetic order in V-doped WSe2 monolayer through free hole carriers. More importantly, the ferromagnetic order is clearly modulated by applying a back gate. Our findings open new opportunities for using two-dimensional transition metal dichalcogenides for future spintronics.