Publication
Title
Direct space structure solution from precession electron diffraction data: resolving heavy and light scatterers in $Pb_{13}Mn_{9}O_{25}$
Author
Abstract
 The crystal structure of a novel compound Pb13Mn9O25 has been determined through a direct space structure solution with a Monte-Carlo-based global optimization using precession electron diffraction data (a=14.177(3) Å, c=3.9320(7) Å, SG P4/m, RF=0.239) and compositional information obtained from energy dispersive X-ray analysis and electron energy loss spectroscopy. This allowed to obtain a reliable structural model even despite the simultaneous presence of both heavy (Pb) and light (O) scattering elements and to validate the accuracy of the electron diffraction-based structure refinement. This provides an important benchmark for further studies of complex structural problems with electron diffraction techniques. Pb13Mn9O25 has an anion- and cation-deficient perovskite-based structure with the A-positions filled by the Pb atoms and 9/13 of the B positions filled by the Mn atoms in an ordered manner. MnO6 octahedra and MnO5 tetragonal pyramids form a network by sharing common corners. Tunnels are formed in the network due to an ordered arrangement of vacancies at the B-sublattice. These tunnels provide sufficient space for localization of the lone 6s2 electron pairs of the Pb2+ cations, suggested as the driving force for the structural difference between Pb13Mn9O25 and the manganites of alkali-earth elements with similar compositions.
Language
English
Source (journal)
Ultramicroscopy. - Amsterdam
Publication
Amsterdam : 2010
ISSN
0304-3991
Volume/pages
110:7(2010), p. 881-890
ISI
000280050900023
Full text (Publisher's DOI)
Full text (publisher's version - intranet only)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address