Metal-insulator transition and thermoelectric properties in the system (R sub 1-x Ca sub x )MnO sub 3-. delta. (R: Tb, Ho, Y)

Journal Article · Wed May 01 04:00:00 EDT 1991 · Journal of Solid State Chemistry; (United States)

DOI:https://doi.org/10.1016/0022-4596(91)90248-G· OSTI ID:7110847

Kobayashi, T; Takizawa, H; Endo, T; Sato, T; Shimada, M ^[1]; Taguchi, H; Nagao, M ^[2]

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1. Tohoku Univ., Aobaku, Sendai (Japan)
2. Okayama Univ. (Japan)

(R{sub 1-x}Ca{sub x})MnO{sub 3-{delta}}(R: Tb, Ho, Y) solid solutions with the orthorhombic perovskite-type structure were synthesized and their electrical resistivity and thermoelectric power were measured in the temperature range 80 to 1000 K. At low temperature, the electrical properties of (R{sub 1-x}Ca{sub x})MnO{sub 3-{delta}} are explained by the variable range hopping of electrons model. At high temperature, hopping conduction occurs in composition range 0.4{le}x{le}0.6, while metal-insulator transition occurs in the range 0.7{le}x{le}0.9. Transition temperature increases with increasing average Mn-O distance. It is concluded that the increase in Mn-O distance enhances the magnitude of the electrostatic field, and consequently the transition temperature is raised. (R{sub 1-x}Ca{sub x})MnO{sub 3-{delta}}(R: Tb, Ho, Y, 0.7 {le}x{le}0.9) are candidates as high temperature thermoelectric conversion materials.

• OSTI ID: 7110847
• Journal Information: Journal of Solid State Chemistry; (United States), Journal Name: Journal of Solid State Chemistry; (United States) Vol. 92:1; ISSN 0022-4596; ISSN JSSCB
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360204* -- Ceramics
Cermets
& Refractories-- Physical Properties
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
CHALCOGENIDES
CONVERSION
CRYSTAL LATTICES
CRYSTAL STRUCTURE
DATA
DIRECT ENERGY CONVERSION
DISPERSIONS
ELECTRICAL EQUIPMENT
ELECTRICAL INSULATORS
ELECTRICAL PROPERTIES
ELEMENTS
ENERGY CONVERSION
EQUIPMENT
EXPERIMENTAL DATA
HOLMIUM COMPOUNDS
HOLMIUM OXIDES
INFORMATION
MANGANESE COMPOUNDS
MANGANESE OXIDES
METALS
MINERALS
MIXTURES
NUMERICAL DATA
ORTHORHOMBIC LATTICES
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PEROVSKITE
PEROVSKITES
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
SOLID SOLUTIONS
SOLUTIONS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K
TEMPERATURE RANGE 0400-1000 K
TERBIUM COMPOUNDS
TERBIUM OXIDES
THERMOELECTRIC CONVERSION
THERMOELECTRIC PROPERTIES
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES