  The effects of strain and hydrogenation on the electronic and magnetic
properties of monolayers of Ta based dichalcogenides (TaX2; X = S, Se, Te) are
investigated using density-functional theo-ry. We predict a complex scenario of
strain-dependent magnetic phase transitions involving par-amagnetic,
ferromagnetic, and modulated antiferromagnetic states. Covering one of the two
chalcogenide surfaces with hydrogen switches the antiferromagnetic/nonmagnetic
TaX2 mono-layers to a semiconductor. Our research opens new pathways towards
the manipulation of mag-netic properties for future optoelectronics and
spintronics applications.
