Magnetism of Ta dichalcogenide monolayers tuned by strain and hydrogenation

The effects of strain and hydrogenation on the electronic, magnetic, and optical properties of monolayers of Ta based dichalcogenides (TaX2; X = S, Se, and Te) are investigated using densityfunctional theory. We predict a complex scenario of strain-dependent magnetic phase transitions involving paramagnetic, ferromagnetic, and modulated antiferromagnetic states. Covering one of the two chalcogenide surfaces with hydrogen switches the antiferromagnetic/nonmagnetic TaX2 monolayers to a semiconductor, and the optical behavior strongly depends on strain and hydrogenation. Our research opens pathways towards the manipulation of magnetic as well as optical properties for future spintronics and optoelectronics applications. (C) 2015 AIP Publishing LLC.