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Schlagwörter:
Carboferrate
Zusammenfassung:
Abstract The carboferrates RE15[Fe8C25] (RE=Dy, Ho) were prepared from mixtures of the elements by arc-melting followed with subsequent annealing at 1373xa0;K. The crystal structures were determined from single crystal X-ray diffraction data and revealed an isotypic relationship to Er15[Fe8C25] (hP48, P321). The main feature of the crystal structure is given by Fe6 cluster units characterized by covalent Fe–Fe bonding interactions. 57Fe Mössbauer spectra of Dy15[Fe8C25] were fitted by three subspectra with relative spectral weights of about 3:3:2 which is in general agreement with the crystal structure. Below 50xa0;K, an onset of magnetic hyperfine fields at the three iron sites is observed which is supposed to be caused by dipolar fields arising from neighboring, slowly relaxing Dy magnetic moments.