Transport and magnetic properties of La{sub 2}NiO{sub 4+{delta}} (0 {le} {delta} {le} 0.25)

Journal Article · Mon Jul 01 04:00:00 EDT 1996 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1996.0226· OSTI ID:494445

Demourgues, A; Dordor, P; Doumerc, J P ^[1]

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1. CNRS, Pessac (France); and others

Materials with La{sub 2}NiO{sub 4+{delta}} composition, {delta} ranging between 0 and 0.25, have been prepared either by solid state reaction or electrochemical oxidation; their electrical conductivity, thermoelectric power, and magnetic susceptibility behaviors are reported. The compounds remain semiconducting in the whole range of composition and, at low temperature, the resistivity increases with {delta}. The sign of the Seebeck coefficient changes for {delta} {approx} 0.2 and the thermal variation shows complex behavior. La{sub 2}NiO{sub 4.03} exhibits a thermally activated hopping and an antiferromagnetic ordering. When {delta} increases, variable range hopping or nearest neighbor hopping, involving at least two types of carriers, can account for the transport properties. The magnetic behavior of materials with {delta} {le} 0.18 reveals either 3D or 2D magnetic correlations whereas the susceptibility of La{sub 2}NiO{sub 4.25} (La{sub 8}Ni{sub 4}O{sub 17}) follows a Curie-Weiss law below 170 K; a change in the electronic configuration of the nickel ions arises beyond this temperature.

• OSTI ID: 494445
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 2 Vol. 124; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CURIE-WEISS LAW
ELECTRIC CONDUCTIVITY
LANTHANUM OXIDES
MAGNETIC SUSCEPTIBILITY
NICKEL OXIDES
OXIDATION
SEEBECK EFFECT
SEMICONDUCTOR MATERIALS
STOICHIOMETRY
THERMOELECTRIC CONVERSION