Ferrite Bi13Ba2Sr25Fe13O66: A Double Collapsed Structure Derived from the "2201-0201" Intergrowth Bi2Sr4Fe2O10
✍ Scribed by M. Hervieu; M.T. Caldes; C. Michel; D. Pelloquin; B. Raveau
- Publisher
- Elsevier Science
- Year
- 1995
- Tongue
- English
- Weight
- 958 KB
- Volume
- 118
- Category
- Article
- ISSN
- 0022-4596
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✦ Synopsis
A new ferrite, (\mathrm{Bi}{13} \mathrm{Ba}{2} \mathrm{Sr}{25} \mathrm{Fe}{13} \mathrm{O}{66}), has been synthesized. It crystallizes in the space group (C 2 / c) with (a=39.108) (5) (\AA, b=5.4371) (5) (\AA, c=37.223) (5) (\AA, \beta=114.9^{\circ}) (1). A structural model has been established, using high-resolution electron microscopy. It can be described as a double collapsed structure derived from the "2201-0201" intergrowth (\mathrm{Bi}{2} \mathrm{Sr}{4} \mathrm{Fe}{2} \mathrm{O}{10}). Another description of this structure is presented: it consists of stair-like (\mathrm{Bi}{2} \mathrm{O}{2}) layers parallel to (001) intergrown with (\mathrm{K}{2} \mathrm{NiF}{4})-type layers. The stairs that form the bismuth oxygen layers are 7 bismuth atoms wide, whereas the (\mathrm{K}{2} \mathrm{NiF}{4}) layers are (13 \mathrm{FeO}{6}) octahedra thick, so that this structure can be considered as the " (m=7, n=13) " members of a very promising series of ferrites (\left(\mathrm{Bi}{2-x} \mathrm{Ba}{x} \mathrm{O}{2}\right){m}\left(\mathrm{Sr}{2-x} \mathrm{Ba}{x} \mathrm{FeO}{4}\right){n}). Extended defects involving longitudinal intergrowth of two (m) and (\boldsymbol{m}^{\prime}) members are observed, as well as antiphase boundaries and "SrO" intergrowths. 1995 Academic Press, Inc.