Structural, magnetic and electronic properties of LaNi{sub 0.5}Fe{sub 0.5}O{sub 3} in the temperature range 5-1000 K

Journal Article · Fri Aug 15 04:00:00 EDT 2008 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2008.03.041· OSTI ID:21128381

Gateshki, M ^[1]; Suescun, L ^[2]; Kolesnik, S; Mais, J ^[3]; Swierczek, K ^[2]; Short, S ^[2]; Dabrowski, B ^[2]

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1. Bragg Institute, Australian Nuclear Science and Technology Organization, Menai, NSW 2234 (Australia)
2. Materials Science Division, Argonne National Laboratory, Argonne, IL 60439 (United States)
3. Physics Department, Northern Illinois University, DeKalb, IL 60115 (United States)

The structure, magnetism, transport and thermal expansion of the perovskite oxide LaNi{sub 0.5}Fe{sub 0.5}O{sub 3} were studied over a wide range of temperatures. Neutron time-of-flight data have shown that this compound undergoes a first-order phase transition between {approx}275 and {approx}310 K. The structure transforms from orthorhombic (Pbnm) at low temperatures to rhombohedral (R3-bar c) above room temperature. This phase transition is the cause for the previously observed co-existence of phases at room temperature. The main structural modification associated with the phase transition is the change of tilting pattern of the octahedra from a{sup +}b{sup -}b{sup -} at low temperatures to a{sup -}a{sup -}a{sup -} at higher. Magnetic data strongly suggests that a spin-glass magnetic state exists in the sample below 83 K consistent with the absence of magnetic ordering peaks in the neutron data collected at 30 K. At high temperatures the sample behaves as a small polaron electronic conductor with two regions of slightly different activation energies of 0.07 and 0.05 eV above and below 553 K, respectively. The dilatometric data show an average thermal expansion coefficient of 14.7x10{sup -6} K{sup -1} which makes this material compatible with frequently used electrolytes in solid oxide fuel cells. - Graphical abstract: The structure, magnetism, transport and thermal expansion of the perovskite oxide LaNi{sub 0.5}Fe{sub 0.5}O{sub 3} were studied over a wide range of temperatures. Its structure transforms from orthorhombic at low temperatures to rhombohedral above room temperature. The resistivity and dilatometric data show that this material is compatible with frequently used electrolytes in solid oxide fuel cells.

• OSTI ID: 21128381
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 8 Vol. 181; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
ACTIVATION ENERGY
IRON COMPOUNDS
LANTHANUM COMPOUNDS
MAGNETISM
NICKEL COMPOUNDS
ORTHORHOMBIC LATTICES
OXIDES
PEROVSKITE
PHASE TRANSFORMATIONS
SOLID OXIDE FUEL CELLS
SPIN GLASS STATE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
THERMAL EXPANSION
TIME-OF-FLIGHT METHOD
TRIGONAL LATTICES