Competing antiferromagnetic order in transition metal dichalcogenides FexNbS2*

The transition metal dichalcogenides (TMDCs) have attracted a great deal of attention due to their potential for new spintronic technologies. Intercalated variants T_xMA₂ (T=3d transition metal; M = Ta, Nb; A = S, Se) with x=⅓, which are of particular interest, show a rich array of magnetic phenomena. Chiral magnetism has been reported in Cr and Mn intercalation complexes that give rise to anomalous hall effect. The V complex exhibits a uniaxial chiral magnetism. Unlike these materials, Fe_xNbS₂ is antiferromagnetic (AFM) with strong anisotropy along the c axis. Interestingly, devices made from Fe_1/3+dNbS₂ crystal exhibit novel spintronic properties that are coupled to the antiferromagnetic transition and sensitive to the intercalation ratio. We comprehensively investigated the magnetic structures for two successive transitions at and off- stoichiometry. We found that the sensitivity of the transport properties is reflected in the x-dependence of magnetic ground state, where distinct AFM orders compete over a small range of the intercalation ratio.