Magnetic Ordering in One-Dimensional System CoNb₂O₆with Competing Interchain Interactions

Abstract

We investigated the formation of three-dimensional (3D) magnetic ordering in a quasi-1D ferromagnetic chain system CoNb 2 O 6 by neutron scattering. With decreasing temperature below T 1 ∼3 K in the helical magnetic phase, anomalous broadening of magnetic satellite reflections was observed in the directions perpendicular to the 1D magnetic chain, with a rapid change in the propagation wave number of helical magnetic ordering. Furthermore, in the antiferromagnetic phase below T 2 ∼1.9 K, CoNb 2 O 6 exhibits a pronounced 2D magnetic character. These features result from the competition between interchain exchange interaction and Co 2+ single-ion anisotropy in this compound.