MAGNETIC-PROPERTIES OF A 2D FERRIMAGNETIC MIXED-VALENCE IRON FLUOROPHOSPHATE

[Fe2+Fe3+F2(HPO4)(2)(H2O)(2) . ethylenediamine] labelled ULM-10 which was recently synthesized by hydrothermal method, is a mixed-valence ir on fluorophosphate. Mossbauer data are consistent with the presence of equiprobable ferrous and ferric sites, both in high-spin state, locat ed in [Fe2+O2F2(H2O)(2)] and [Fe3+O4F2] octahedra, respectively. Magne tic susceptibility measurements and in-field Mossbauer spectra reveal that ULM-10 behaves as a two-dimensional ferrimagnet below 28 (+/-2) K . Hyperfine data of ULM-10 are compared with those of [Fe3+O4F2] octah edra-containing compounds.