Kinetic effects in manganites La{sub 1-x}Ag{sub y}MnO{sub 3} (y {<=} x)

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Journal of Experimental and Theoretical Physics

DOI:https://doi.org/10.1134/S1063776107100111· OSTI ID:21075693

Kamilov, I K; Aliev, A M; Batdalov, A B; Abdulvagidov, Sh B ^[1]; Mel'nikov, O V; Gorbenko, O Yu; Kaul', A R ^[2]

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1. Russian Academy of Sciences, Institute of Physics, Dagestan Research Center (Russian Federation)
2. Moscow State University (Russian Federation)

We have measured the resistivity, magnetoresistance, and thermopower of ceramic manganite samples La{sub 1-x}Ag{sub y}MnO{sub 3} (y {<=} x) doped with silver as functions of temperature (4.2-350 K) and magnetic field (up to 26 kOe). A metal-insulator phase transition is observed in all investigated samples at temperatures close to room temperature. The behavior of the resistivity and thermopower in the high-temperature paramagnetic region is interpreted using the concept of small radius polaron; the activation energy decreases with increasing doping level. The resistivity in the low-temperature ferromagnetic region is approximated by the expression {rho}{sub FM}(T) = {rho}{sub 0} + AT{sup 2} + BT{sup 4.5} presuming the existence of electron-electron and electron-magnon interactions. A resistivity minimum and a strong magnetoresistive effect are observed at low temperatures. The latter effect is associated with scattering of charge carriers at grain boundaries, which are antiferromagnetically ordered relative to one another. The temperature dependence of thermopower in the magnetically ordered phase is described in the framework of a model taking into account the drag of charge carriers by magnons.

• OSTI ID: 21075693
• Journal Information: Journal of Experimental and Theoretical Physics, Vol. 105, Issue 4; Other Information: DOI: 10.1134/S1063776107100111; Copyright (c) 2007 Nauka/Interperiodica; Article Copyright (c) 2007 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7761
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ACTIVATION ENERGY
CERAMICS
CHARGE CARRIERS
DOPED MATERIALS
ELECTRONS
GRAIN BOUNDARIES
LANTHANUM COMPOUNDS
MAGNETIC FIELDS
MAGNETORESISTANCE
MAGNONS
MANGANATES
PARAMAGNETISM
PHASE TRANSFORMATIONS
SILVER
SILVER COMPOUNDS
TEMPERATURE DEPENDENCE
TEMPERATURE RANGE 0000-0013 K
TEMPERATURE RANGE 0013-0065 K
TEMPERATURE RANGE 0065-0273 K
TEMPERATURE RANGE 0273-0400 K