Two-dimensional metamagnet composed of a cesium copper octacyanotungstate

X-ray crystal structural analysis indicates that a cyano-bridged Cu–W bimetallic assembly, CsICuII[WV(CN)8] · 0.5H2O, consists of a two-dimensional (2D) double-layered structure, where CsI penetrates between the anionic double-layers. This compound exhibits spontaneous magnetization below a magnetic critical temperature of 40 K and metamagnetic behaviors such as an anomalous magnetization drop below 30 K and a spin–flip transition at 90 Oe. Calculations based on a magnetic dipole–dipole interaction indicate that the magnetic spins of the antiferromagnetic and ferromagnetic configurations are oriented along the c-axis in the bc plane. The calculated energy difference between these two configurations almost corresponds to the energy of the magnetic field of the spin–flip transition.