La and Sr substituted Pr{sub 2}NiO{sub 4+{delta}}: Oxygenation and electrical properties

Journal Article · Sun Jun 01 04:00:00 EDT 1997 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1006/jssc.1997.7402· OSTI ID:589044

Allancon, C; Odier, P; Loup, J P ^[1]; Bassat, J M ^[2]

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1. Centre de Recherches sur la Physique des Hautes Temperatures, Orleans (France)
2. Institut de Chimie de la Matiere Condensee de Bordeaux, Pessac (France)

We report herein results concerning the solid solutions Pr{sub 2-x}M{sub x}NiO{sub 4+{delta}}, M = La, Sr. These two cations are larger than praseodymium and lead to a structural stabilization. The oxygen excess {delta} decreases with x for La and Sr substituted Pr{sub 2}NiO{sub 4+{delta}}. Both cases suggest that structural strain is a leading factor for the oxygenation ability of the title compounds. From the evolution of cell parameters, we suggest a phase transition for La substituted compounds occurring for x {approximately} 1-1.2. Surprisingly, this transition has a negligible effect on transport properties. On the other hand, a charge localization linked to the presence of praseodymium is observed. Owing to charge compensation, the Sr substituted compounds have a quasi-constant hole concentration (formally 50%) for x < 0.5. The Pr{sub 2-x}Sr{sub x}NiO{sub 4+{delta}} solid solution shows an anomalous behavior for x = 0.5 corresponding to Ni{sup 2+}/Ni{sup 3+} = 1. This anomaly combines an enhancement of the c/a ratio, a larger resistivity, and a peak for the activation energy of the resistivity versus T.

• OSTI ID: 589044
• Journal Information: Journal of Solid State Chemistry, Journal Name: Journal of Solid State Chemistry Journal Issue: 1 Vol. 131; ISSN 0022-4596; ISSN JSSCBI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
LANTHANUM OXIDES
NICKEL OXIDES
PRASEODYMIUM OXIDES
SOLID SOLUTIONS
STRONTIUM OXIDES