Synthesis and crystal structure of new layered perovskite compounds: Li{sub 2}La{sub 0.833}(Nb{sub 1.5}Ti{sub 0.5})O{sub 7} and Li{sub 2}La{sub 2.25}(Nb{sub 1.25}Ti{sub 2.75})O{sub 13}
- Univ. du Maine, Le Mans (France). Lab. des Fluorures
Single crystals of Li{sub 2}La{sub 0.833}(Nb{sub 1.5}Ti{sub 0.5})O{sub 7} and Li{sub 2}La{sub 2.25}(Nb{sub 1.25}Ti{sub 2.75})O{sub 13} were grown in the system Li{sub 2}O-La{sub 2}O{sub 3}-Nb{sub 2}O{sub 5}-TiO{sub 2}. Both these compounds crystallize in the space group P4{sub 2}/mmm (No 136), Z = 4: a = 5.5334(2), c = 18.3907(2) {angstrom} and a = 5.4915(6), and c = 33.812(4) {angstrom}, respectively. Their crystal structures, determined from single crystal X-ray diffraction data, are related to the Ruddlesden-Popper phases A{sub n+1}B{sub n}O{sub 3n+1}, which could be better written here as Li{sub 2}[A{sub x}B{sub n}O{sub 3n+1}]: Li{sub 2}La{sub 0.833}(Nb{sub 1.5}Ti{sub 0.5})O{sub 7} is an n = 2 member and Li{sub 2}La{sub 2.25}(Nb{sub 1.25}Ti{sub 2.75})O{sub 13} corresponds to an n = 4 member. In both structures, Nb{sup 5+} and Ti{sub 4+} ions statistically occupy distorted B octahedral sites of the perovskite, La{sup 3+} ions partially fill the cages of the perovskite, and Li{sup +} ions are found in tetrahedral coordination between the perovskite layers.
- OSTI ID:
- 352416
- Journal Information:
- Materials Research Bulletin, Vol. 34, Issue 2; Other Information: PBD: 15 Jan 1999
- Country of Publication:
- United States
- Language:
- English
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