Metal-insulator transition in the system (Ca/sub 1-x/La/sub x/)MnO/sub 2. 97 (0. 05 less than or equal to x less than or equal to 0. 4)
The electrical resistivity of (Ca/sub 1-x/La/sub x/)MnO/sub 2.97/ (0.05 less than or equal to x less than or equal to 0.4) was measured in the temperature range from 80 to 1000 K. All manganates are n-type semiconductors below room temperature. Below 125 K, the electrical resistivity follows the Mott's T/sup -1/4/ law indicating the possible occurrence of variable hopping of electrons due to Anderson localization. Above ca. 400-450 K, all manganates exhibit a metal-insulator transition without crystallographic change. From the results of magnetic measurement, the mechanism of the metal-insulator transition is explained by the band model of covalency criterion for localized vs collective electrons in oxides with the perovskite structure.
- Research Organization:
- Osaka Prefectural Industrial Research Institute, Japan
- OSTI ID:
- 5405578
- Journal Information:
- J. Solid State Chem.; (United States), Vol. 63:2
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
CALCIUM COMPLEXES
ELECTRIC CONDUCTIVITY
LANTHANUM COMPLEXES
MANGANESE OXIDES
EXPERIMENTAL DATA
HIGH TEMPERATURE
LOW TEMPERATURE
MEDIUM TEMPERATURE
N-TYPE CONDUCTORS
POWDERS
VERY HIGH TEMPERATURE
X-RAY DIFFRACTION
ALKALINE EARTH METAL COMPLEXES
CHALCOGENIDES
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
ELECTRICAL PROPERTIES
INFORMATION
MANGANESE COMPOUNDS
MATERIALS
NUMERICAL DATA
OXIDES
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
RARE EARTH COMPLEXES
SCATTERING
SEMICONDUCTOR MATERIALS
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties