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}

Journal Article · Fri Jan 15 04:00:00 EST 1999 · Materials Research Bulletin

DOI:https://doi.org/10.1016/S0025-5408(99)00016-1· OSTI ID:352416

Crosnier-Lopez, M P; Duroy, H; Fourquet, J L ^[1]

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1. 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, Journal Name: Materials Research Bulletin Journal Issue: 2 Vol. 34; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CRYSTAL STRUCTURE
LANTHANUM OXIDES
LATTICE PARAMETERS
LITHIUM OXIDES
MONOCRYSTALS
NIOBIUM OXIDES
PEROVSKITE
SYNTHESIS
TITANIUM OXIDES
X-RAY DIFFRACTION