Metal-insulator transition in the system (Nd/sub 1-x/Ca/sub x/)MnO/sub 2. 99/ (0. 5 less than or equal to x less than or equal to 0. 9)

Journal Article · Sat Oct 01 00:00:00 EDT 1988 · J. Solid State Chem.; (United States)

DOI:https://doi.org/10.1016/0022-4596(88)90221-6· OSTI ID:6257998

Taguchi, H; Nagao, M; Shimada, M

The electrical resistivity of (Nd/sub 1-x/Ca/sub x/)MnO/sub 2.99/ (0.5 less than or equal to x less than or equal to 0.9) was measured in the temperature range 80 to 850 K. At low temperature, all manganates are n-type semiconductors, and the electrical resistivity follows the Mott's T/sup -1/4/ law, indicating the possible occurrence of variable range hopping of electrons due to Anderson localization. At high temperature, all manganates exhibit a metal-insulator transition without any crystallographic change. From the results of the magnetic susceptibility, it is concluded that the metal-insulator transition is caused by a change of the spin state of trivalent manganese ion in (Nd/sub 1-x/Ca/sub x/)MnO/sub 2.99/.

• Research Organization: Okayama Univ. (Japan)
• OSTI ID: 6257998
• Journal Information: J. Solid State Chem.; (United States), Vol. 76:2
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CALCIUM OXIDES
ELECTRIC CONDUCTIVITY
MANGANESE OXIDES
NEODYMIUM OXIDES
CRYSTAL-PHASE TRANSFORMATIONS
HIGH TEMPERATURE
LOW TEMPERATURE
MEDIUM TEMPERATURE
ALKALINE EARTH METAL COMPOUNDS
CALCIUM COMPOUNDS
CHALCOGENIDES
ELECTRICAL PROPERTIES
MANGANESE COMPOUNDS
NEODYMIUM COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
RARE EARTH COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
360204* - Ceramics
Cermets
& Refractories- Physical Properties