Large negative magnetoresistance in the antiferromagnetic rare-earth dichalcogenide EuTe2

We report the synthesis and characterization of a rare-earth dichalcogenide EuTe2. An antiferromagnetic transition was found at T-N = 11 K. The antiferromagnetic order can be tuned by an applied magnetic field to access a first-order spin-flop transition and a spin-flip transition. These transitions are associated with a large negative magnetoresistance with a change of magnitude of resistivity over five orders. Magnetic susceptibility, heat capacity, and Hall coefficient measurements reveal that the moments of Eu2+ align along the c axis and holes are the majority carriers. Furthermore, density functional theory calculations demonstrate that the carriers near the Fermi surface mainly originate from the Te 5p orbitals and the magnetism is dominated by localized electrons from the Eu 4f orbitals. Our results suggest that EuTe2 is an A-type antiferromagnetic material with large negative magnetoresistance.