Crystal structure and charge distribution of YbFeMnO4

Autor: Junji Iida, Massimo Nespolo, Mitsumasa Isobe, Noboru Kimizuka
Přispěvatelé: Laboratoire de Cristallographie et modélisation des matériaux minéraux et biologiques (LCM3B), Université Henri Poincaré - Nancy 1 (UHP)-Centre National de la Recherche Scientifique (CNRS)
Rok vydání: 2000
Předmět:
Zdroj: Acta Crystallographica Section B: Structural Science
Acta Crystallographica Section B: Structural Science, International Union of Crystallography, 2000, 56 (5), pp.805-810. ⟨10.1107/S0108768100005383⟩
ISSN: 0108-7681
Popis: The structure of synthetic YbFeMnO4 has been refined by single-crystal X-ray diffraction. Space group R\bar 3m, a = 3.4580 (1), c = 25.647 (3) Å, V = 265.59 (3) Å3, Z = 3. Yb is in octahedral coordination, whereas Fe and Mn are disordered on a single crystallographic type of trigonal bipyramid, in which the cation is off-centred from the basal plane. Assuming perfect stoichiometry, R 1 = 0.0195, but the charge distribution (CD) analysis suggests incomplete occupation of the Yb site. Refinement of the occupancy lowers R 1 to 0.0175, resulting in s.o.f.(Yb) = 0.963 (3), with a significant improvement of the Fourier difference. The electroneutrality is likely preserved through incomplete occupancy of one of the two oxygen sites: the compound is thus non-stoichiometric, with the formula Yb0.963FeMnO3.945. Another mechanism for preserving the electroneutrality is the oxidation of a small amount of Mn2+ to Mn3+, which is, however, less probable because of the reduction conditions in which the sample was synthesized. Both models give a satisfactorily CD result, but they cannot be definitively distinguished by X-ray data.
Databáze: OpenAIRE
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