Large negative magnetoresistance induced by anionic solid solutions in two-dimensional spin-frustrated transition metal chalcogenides

We report an anionic solid solution process that induces frustrated magnetic structures within two-dimensional transition metal chalcogenides, which leads to huge negative magnetoresistance effects. Ultrathin nanosheets of TiTe2-xIx solid solutions, which are a new class of inorganic two-dimensional magnetic material, exhibit negative magnetoresistance with a value of up to -85%, due to the spin-dependent scattering effects of local Ti3+ 3d1 moments that are antiferromagnetically coupled. Moreover, TiTe2-xIx serials show unique transport behaviors with continuous evolution from metallic to semiconducting states. We anticipate that anionic doping will be a powerful tool for optimizing the intrinsic physical properties of two-dimensional transition metal chalcogenide system.