Density functional theory prediction on magnetism in Gd-doped monolayer MoS2

• Replacing Mo with Gd in monolayer MoS2 can produce p-type semiconducting.
• Ferromagnetism for two Gd at the first and third nearest neighbor sites appears.
• The hole is the main factor for ferromagnetic exchange interaction in Mo14Gd2S32.

Magnetism of Gd-doped monolayer MoS2 is predicted by first-principles calculations. Gd-doped monolayer MoS2 is p-type semiconducting and is energetically favorable to form under S-rich condition. As two Gd are incorporated into 4×4 monolayer MoS2, Gd–Gd magnetic coupling cannot be only attributed to Gd–Gd distance, which is also related to strong directional nature of electronic structure or chemical bonding in MoS2. The most stable magnetic configuration is paramagnetic at the second nearest sites. For two Gd spins at the first and third nearest sites, the magnetic moment from matrix is large. Meanwhile, hole is the main factor for ferromagnetic interaction in Mo14Gd2S32.