Structure and Magnetic Properties of Gadolinium Hexacyanoferrate Prussian Blue Analogue

The structure of gadolinium hexacyanoferrate Prussian blue analogue GdFe(CN)₆]·4H₂O was investigated by powder x-ray diffraction technique using the Rietveld structure refinement method. Obtained results have confirmed pseudohexagonal symmetry of the compound with lattice parameters a = 7.394(4), b = 12.836(6) and c = 13.666(6). The negative value of IS in Mössbauer spectrum is due to the presence of cyano groups. Magnetic susceptibility above T = 20K obeys Curie-Weiss law. Value of effective magnetic moment _eff = 7.19 _B is lower than the expected value for a free Gd³⁺ ion ( _eff = 7.94 _B). Differences between FC and ZFC behavior of magnetic susceptibility indicate a spin-glass like magnetic arrangement. Our results support prediction that the material orders ferrimagnetically below T _c = 2.3K.