X-ray resonant scattering study on the minor canted moment of spin-1 1 dimensional chain system NiTe₂O₅

A minor canted component of antiferromagnetic order below T_N ~ 30.5 K of NiTe₂O₅ was investigated by the soft x-ray resonant scattering on Ni L₃ edge. It is a S=1 (Ni²⁺) magnetic insulator composed of edge shared NiO₆ one dimensional chains along b axis with four Ni atoms per period. The nearly 90° superexchange path between two adjacent Ni stabilizes intra-chain ferromagnetic order along b axis, which is ordered antiferromagnetically between adjacent chains. A detailed analysis on the azimuthal and polarization dependence of the (010) structural forbidden peak reveals that the resonant peak is a result of interference between the anisotropic tensor susceptibility and the magnetic resonant scattering amplitude from 'up-down-down-up' minor canted moment in ac plane. The non-collinear spin structure is related to the distortion of Ni-O-Ni bonding to induce non-zero Dzyaloshinskii-Moriya interaction, and rather large spin-orbit coupling of Ni 3d orbital.