A study of the real structure of intermetallic compounds R2Fe17 (R = Ce, Lu) using neutron powder diffraction, NMR and NGR methods

The real structure of the Lu2Fe17 compound was shown to be a disordered var iant of the Th2Ni17-type structure for which the exchange of places between Y in 2b-sites and 'dumbbells' of Fe (4f sites) is specific as well as a pa rtial occupation of 4e-position by Fe atoms. Besides, some quantity of Y im plants in 2c sites, causing a distortion inside the plane and splitting of Fe 12j-position into two. The real crystal structure of the Ce2Fe17 compoun d is close to an ideal one of the Th2Zn17-type. The results of neutron diff raction investigation, which allow one to determine fine structure distorti ons of the lattices "in the mean" are in goad agreement with the NMR and NG R data reflecting local (in terms of interatomic spacings) changes. (C) 200 0 Elsevier Science B.V. All rights reserved.