A family of quasi-one-dimensional zigzag spin-chain Ba2REV3O11 (RE = Pr, Nd, and Gd–Ho) compounds

The diverse exotic magnetic states realized in one-dimensional (1D) spin-chain systems have motivated the extensive exploration of new materials with a 1D spin-chain motif, while 1D magnets comprising rare-earth (RE) ions are largely unexplored compared with their 3d transition metal (TM)-based counterparts. Herein, we report the synthesis and magnetic properties of a family of RE-based zigzag spin-chain Ba2REV3O11 compounds (RE = Pr, Nd, and Gd–Ho) crystallized into a monoclinic structure with the space group P21/a, wherein spin chains are connected by edge-sharing REO6 octahedra along the b axis and well separated by nonmagnetic VO4 tetrahedra extended within the ac plane. Moreover, the nearest neighbor (NN) intrachain RE–RE distance (dintra, ∼3.856–3.952 Å) is much shorter than the NN interchain separation (dinter, ∼5.191–5.246 Å), supporting quasi-1D characteristics. Magnetic susceptibility and isothermal magnetization measurements revealed that only Ba2DyV3O11 displays a magnetic anomaly at ∼2.9 K and other family members do not order down to 1.8 K. Among them, Ba2GdV3O11 with a spin-only magnetic moment (S) of 7/2 exhibits a long-range magnetic order with TN ∼ 0.67 K and a large magnetocaloric effect with a maximum magnetic entropy change (ΔSM) of 14.3 J K−1 (mol-Gd)−1 under a magnetic field change (Δμ0H) of 4 T at a temperature of ∼1 K, making it a suitable material for magnetic refrigeration in sub-Kelvin temperature regimes.