Nanoparticles-decorated 2D transition metal dichalcogenides with room-temperature ferromagnetic response.

Ferromagnetism in two-dimensional (2D) van der Waals materials has attracted increasing attention due to its potential for developing a new generation of spintronic devices. In this work, we propose an alternative approach that consists in decorating 2D TMD materials with nanoparticles of manganese oxide. The nanoparticles were deposited on the surface of monolayer MoSe2 using a chemical vapor deposition technique. Micro-Raman and PL spectroscopy were used to study their optical properties; while the morphology, chemical composition and thickness of the samples were characterized via SEM, STEM and AFM, respectively. Magnetic measurements reveal a weak ferromagnetic behavior in individual MoSe2 films. Similarly, weak ferromagnetism is observed for MnOx nanoparticles deposited on a SiO2 substrate. However, when the MnOx nanoparticles are deposited on 2D MoSe2, the hybrid MnOx/MoSe2 system displays enhanced room-temperature ferromagnetism, suggesting a strong magnetic exchange coupling between the two material components. A detailed analysis on the temperature dependence of saturation magnetization and coercive field indicates stronger magnetic coupling at lower temperatures. Our results provide an alternative route to induce room-temperature ferromagnetism in 2D systems.