Magnetic and electrical properties of quadruple perovskites with 12 layer structures Ba{sub 4}LnM{sub 3}O{sub 12} (Ln=rare earths; M=Ru, Ir): The role of metal-metal bonding in perovskite-related oxides

Journal Article · Wed Sep 15 00:00:00 EDT 2010 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2010.06.023· OSTI ID:21483664

Shimoda, Yuki; Doi, Yoshihiro; Wakeshima, Makoto ^[1]; Hinatsu, Yukio ^[1]

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1. Division of Chemistry, Hokkaido University, Sapporo 060-0810 (Japan)

Structures and magnetic and electrical properties of quadruple perovskites containing rare earths Ba{sub 4}LnM{sub 3}O{sub 12} (Ln=rare earths; M=Ru, Ir) were investigated. They crystallize in the 12L-perovskite-type structure. Three MO{sub 6} octahedra are connected to each other by face-sharing and form a M{sub 3}O{sub 12} trimer. The M{sub 3}O{sub 12} trimers and LnO{sub 6} octahedra are alternately linked by corner-sharing, forming the perovskite-type structure with 12 layers. For Ln=Ce, Pr, and Tb, both the Ln and M ions are in the tetravalent state (Ba{sub 4}Ln{sup 4+}M{sup 4+}{sub 3}O{sub 12}), and for other Ln ions, Ln ions are in the trivalent state and the mean oxidation state of M ions is +4.33 (Ba{sub 4}Ln{sup 3+}M{sup 4.33+}{sub 3}O{sub 12}). All the Ba{sub 4}Ln{sup 3+}Ru{sup 4.33+}{sub 3}O{sub 12} compounds show magnetic ordering at low temperatures, while any of the corresponding iridium-containing compounds Ba{sub 4}Ln{sup 3+}Ir{sup 4.33+}{sub 3}O{sub 12} is paramagnetic down to 1.8 K. Ba{sub 4}Ce{sup 4+}Ir{sup 4+}{sub 3}O{sub 12} orders antiferromagnetically at 10.5 K, while the corresponding ruthenium-containing compound Ba{sub 4}Ce{sup 4+}Ru{sup 4+}{sub 3}O{sub 12} is paramagnetic. These magnetic results were well understood by the magnetic behavior of M{sub 3}O{sub 12}. The effective magnetic moments and the entropy change for the magnetic ordering show that the trimers Ru{sup 4.33+}{sub 3}O{sub 12} and Ir{sup 4+}{sub 3}O{sub 12} have the S=1/2 ground state, and in other cases there is no magnetic contribution from the trimers Ru{sup 4+}{sub 3}O{sub 12} or Ir{sup 4.33+}{sub 3}O{sub 12}. Measurements of the electrical resistivity of Ba{sub 4}LnM{sub 3}O{sub 12} and its analysis show that these compounds demonstrate two-dimensional Mott-variable range hopping behavior. - Graphical abstract: Structures and magnetic and electrical properties of quadruple perovskites containing rare earths Ba{sub 4}LnM{sub 3}O{sub 12} (Ln=rare earths; M = Ru, Ir) were investigated. They crystallize in the 12L-perovskite-type structure. All the Ba{sub 4}Ln{sup 3+}Ru{sup 4.33+}{sub 3}O{sub 12} compounds show magnetic ordering at low temperatures, while any of the corresponding iridium-containing compounds Ba{sub 4}Ln{sup 3+}Ir{sup 4.33+}{sub 3}O{sub 12} is paramagnetic down to 1.8 K. Ba{sub 4}Ce{sup 4+}Ir{sup 4+}{sub 3}O{sub 12} orders antiferromagnetically at 10.5 K, while the corresponding ruthenium-containing compound Ba{sub 4}Ce{sup 4+}Ru{sup 4+}{sub 3}O{sub 12} is paramagnetic. These magnetic results were well understood by the magnetic behavior of M{sub 3}O{sub 12}. The electrical resistivity measurements show that these compounds demonstrate two-dimensional Mott-variable range hopping behavior.

• OSTI ID: 21483664
• Journal Information: Journal of Solid State Chemistry, Vol. 183, Issue 9; Other Information: DOI: 10.1016/j.jssc.2010.06.023; PII: S0022-4596(10)00274-4; Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM COMPOUNDS
ELECTRIC CONDUCTIVITY
ENTROPY
IRIDIUM COMPOUNDS
IRIDIUM IONS
LAYERS
MAGNETIC MOMENTS
MAGNETIC PROPERTIES
MAGNETIZATION
OXIDES
PARAMAGNETISM
PEROVSKITE
RARE EARTH COMPOUNDS
RUTHENIUM COMPOUNDS
RUTHENIUM IONS
SPECIFIC HEAT
TEMPERATURE RANGE 0000-0013 K
ALKALINE EARTH METAL COMPOUNDS
CHALCOGENIDES
CHARGED PARTICLES
ELECTRICAL PROPERTIES
IONS
MAGNETISM
MINERALS
OXIDE MINERALS
OXYGEN COMPOUNDS
PEROVSKITES
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
TEMPERATURE RANGE
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS