Inorganic Chemistry, Vol.57, No.6, 3151-3157, 2018
Syntheses, Structure, and 2/5 Magnetization Plateau of a 2D Layered Fluorophosphate Na3Cu5(PO4)(4)F center dot 4H(2)O
A new two-dimensional (2D) fluorophosphate compound Na3Cu5(PO4)(4)F center dot 4H(2)O with a Cu-5 cluster has been synthesized using a conventional hydrothermal method. The compound crystallizes in the orthorhombic crystal system with space group Pnma. The 2D layered structure is formed by cap-like {Cu-5(PO4)4F} building units consisting of a Cu4O12F cluster plus a residual cap Cu2+ ion. Magnetic susceptibility exhibits a broad maximum at T-2 = 19.2 K due to low-dimensional character followed by a long-range antiferromagnetic ordering at T-1 = 11.5 K, which is further confirmed by the specific heat data. High-field magnetization measurement demonstrates a 2/5 quantum magnetization plateau above 40 T. The ESR data indicate the presence of magnetic anisotropy, in accordance with the 2D structure of the system.