A new ordered oxygen-deficient manganite perovskite: LaBaMn{sub 2}O{sub 5.5}. Crystal and magnetic structure

Journal Article · Thu Apr 01 04:00:00 EST 1999 · Chemistry of Materials

DOI:https://doi.org/10.1021/cm980469h· OSTI ID:347496

Caignaert, V; Millange,; Domenges, B; Raveau, B ^[1]; Suard, E ^[2]

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1. C.N.R.S., Caen (France). Lab. CRISMAT
2. Inst. Laue-Langevin, Grenoble (France)

A new ordered oxygen-deficient perovskite, LaBaMn{sub 2}O{sub 5.5}, has been synthesized, using the topotactic deoxygenation of the ordered LaBaMn{sub 2}O{sub 6} perovskite. The crystal structure of this manganite was solved in the space group Ammm (a = 3.86 {angstrom}, b = 8.19 {angstrom}, c = 15.47 {angstrom}) from neutron powder diffraction data. The [Mn{sub 2}O{sub 5.5}]{sub {infinity}} framework is built up of row of MnO{sub 6} octahedra and MnO{sub 5} pyramids running along {rvec a}. This structure is intermediate between that of the ordered LaBaMn{sub 2}O{sub 6} perovskite and that of LaBaMn{sub 2}O{sub 5}: it consists of ordered barium and lanthanum layers stacked alternatively along {rvec c}, oxygen vacancies being located at the level of the La layers. The magnetic structure is original: manganese spins form ferromagnetic spin-ladders along the {rvec b} axis that are antiferromagnetically coupled along the {rvec a} and {rvec c} axis. The HREM investigation shows the existence of 90{degree} oriented domains and twinning phenomena.

• OSTI ID: 347496
• Journal Information: Chemistry of Materials, Journal Name: Chemistry of Materials Journal Issue: 4 Vol. 11; ISSN CMATEX; ISSN 0897-4756
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ANTIFERROMAGNETIC MATERIALS
BARIUM OXIDES
CRYSTAL STRUCTURE
LANTHANUM OXIDES
LATTICE PARAMETERS
LAYERS
MAGNETIC PROPERTIES
MANGANESE OXIDES
PEROVSKITE
SYNTHESIS