Comprehensive survey of Nd{sup 3+} substitution In La{sub 2}Mo{sub 2}O{sub 9} oxide-ion conductor

Journal Article · Fri May 15 00:00:00 EDT 2009 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/j.jssc.2009.01.016· OSTI ID:21370370

Corbel, Gwenael ^[1]; Durand, Pierrick; Lacorre, Philippe ^[1]

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1. Laboratoire des Oxydes et Fluorures, UMR-6010 CNRS, Universite du Maine, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9 (France)

Differential thermal analysis coupled to temperature-controlled diffraction have given evidence of a topological metastability phenomenon in an extended compositional range of the La{sub 2-x}Nd{sub x}Mo{sub 2}O{sub 9} solid solution. A metastable-stable phase diagram is proposed for this series of LAMOX-type fast oxide-ion conductors. In the Nd range 0<x<=0.35, a freezing of the oxygen/vacancy disorder of the beta-phase at ambient temperature can be achieved through a splat-quenching to water-ice mixture or/and shaping/sintering into pellet. In the intermediate 0.4<=x<=1.2 range, the amount of beta-metastable phase grows upon substitution for powders. The negative impact of beta-metastable to alpha phase transition on conductivity tends to disappear through the partial stabilization of the beta phase by shaping/sintering. - Graphical abstract: Metastable-stable phase diagram of the solid solution La{sub 2-x}Nd{sub x}Mo{sub 2}O{sub 9} determined from DTA. The topological metastability of the high-temperature cubic beta-form which goes back to monoclinic stable alpha-form above 450-500 deg. C is shown in the intermediate range 0.4<=x<=1.2. Above x=1.2, this transition progressively changes into a thermal trace of the postulated Arrhenius/VTF transformation of transport mechanism.

• OSTI ID: 21370370
• Journal Information: Journal of Solid State Chemistry, Vol. 182, Issue 5; Other Information: DOI: 10.1016/j.jssc.2009.01.016; PII: S0022-4596(09)00021-8; Copyright (c) 2009 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
AMBIENT TEMPERATURE
DIFFERENTIAL THERMAL ANALYSIS
DIFFRACTION
FREEZING
ICE
IONIC CONDUCTIVITY
LANTHANUM COMPOUNDS
MOLYBDATES
MONOCLINIC LATTICES
NEODYMIUM COMPOUNDS
NEODYMIUM IONS
PHASE DIAGRAMS
QUENCHING
SINTERING
SOLID SOLUTIONS
STRAINS
TEMPERATURE RANGE 0400-1000 K
VACANCIES
WATER
CHARGED PARTICLES
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DIAGRAMS
DISPERSIONS
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
FABRICATION
HOMOGENEOUS MIXTURES
HYDROGEN COMPOUNDS
INFORMATION
IONS
MIXTURES
MOLYBDENUM COMPOUNDS
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
POINT DEFECTS
RARE EARTH COMPOUNDS
REFRACTORY METAL COMPOUNDS
SCATTERING
SOLUTIONS
TEMPERATURE RANGE
THERMAL ANALYSIS
TRANSITION ELEMENT COMPOUNDS