Publication
Title
Tetrahedral chain order in the $Sr_{2}Fe_{2}O_{5}$ brownmillerite
Author
Abstract
 The crystal structure of the Sr2Fe2O5 brownmillerite has been investigated using electron diffraction and high resolution electron microscopy. The Sr2Fe2O5 structure demonstrates two-dimensional order: the tetrahedral chains with two mirror-related configurations (L and R) are arranged within the tetrahedral layers according to the −L−R−L−R− sequence, and the layers themselves are displaced with respect to each other over 1/2[111] or 1/2[11] vectors of the brownmillerite unit cell, resulting in different ordered stacking variants. A unified superspace model is constructed for ordered stacking sequences in brownmillerites based on the average brownmillerite structure with a = 5.5298(4)Å, b = 15.5875(12)Å, c = 5.6687(4)Å, and (3 + 1)-dimensional superspace group I2/m(0βγ)0s, q = βb* + γc*, 0 ≤ β ≤ 1/2, 0 ≤ γ ≤ 1.
Language
Dutch
Source (journal)
Chemistry of materials / American Chemical Society. - Washington, D.C.
Publication
Washington, D.C. : 2008
ISSN
0897-4756
Volume/pages
20:22(2008), p. 7188-7194
ISI
000261002200039
Full text (Publisher's DOI)
UAntwerpen
 Faculty/Department Research group Publication type Subject Affiliation Publications with a UAntwerp address