Incommensurate magnetic order arising from frustrated interchain interactions in the spin-1/2 chain compound AgCuVO₄

Abstract

Quantum spin chains with competing interactions offer a platform where low dimensionality and frustration—both acting to suppress magnetic order—intersect. We studied magnetic ordering in the spin-(Formula presented) chain compound AgCuVO₄ using muon spin spectroscopy and neutron diffraction. Long-range magnetic order emerges at T_N = 2.0(1) K, which is ∼1/200 of the dominant intrachain coupling J and ∼1/15 of the interchain interactions. The collinear incommensurate amplitude-modulated magnetic structure features a reduced ordered moment of 0.13(3)µ_B, confined to the abplane and modulated along the caxis—perpendicular to the spin chains—indicating frustrated interchain couplings. The low T_N, small moment, and incommensurate order highlight strong frustration, positioning AgCuVO₄ as a model system for exploring frustration in quantum spin chains.