Thank you, Alan.
Yes, I saw the papers. There are two key restrictions given by authors
for the desired structure:
- four oxygen layers with two middle ones having a substitutional
barium and
- no m-plane perpendicular to c direction.
From this point none of the mentioned can suit me.
It is mentioned in several papers as 'early published'
To give an example: J.Phys.Chem, 1963, 67(4), 957 (member with index
n=0)
http://pubs3.acs.org/acs/journals/toc.page?
incoden=jpchax&indecade=3&involume=67&inissue=4
Meilleures salutations,
Ivan
Le Jul 26, 2004, à 10:23, Alan Hewat a écrit :
structure of Ba2Fe8O14 with P-3m1 symmetry and c parameter about 9.6 A?
It is mentioned in several papers as 'early published'
The best ICSD does is BaFe4O7 with P63/m and c parameter 13.8A ie
~sqrt(2) times your c-parameter.
Okamoto, S.;Okamoto, S.I.;Ito, T. The crystal structure of barium
diferrite (1973)
Acta Crystallographica B 29, 832-838 XRef
There are many similar barium ferrites, often with P63/mmc symmetry,
differing in how Fe is ordered in the pyramidal holes. A common
feature appears to be a layer of pairs of FeO4 pyramids joined along c
by a common corner and separated by 0,1,2... layers of edge connected
pyramids eg starting with the simplest where Fe is again Fe+++
Meriani, S. Polymorphism of barium monoferrite, Ba Fe2 O4
Acta Crystallographica B (1972) 28, 1241-1243 XRef
But maybe you know all this... Alan.
Dr Alan W. Hewat, Diffraction Group Leader.
Institut Laue-Langevin, BP 156X Grenoble FRANCE 38042
fax (33)4.76.20.76.48 tel (33)4.76.20.72.13 (or .26 Mme Guillermet)
<[EMAIL PROTECTED]> http://www.ill.fr/dif/AlanHewat.htm
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