Transport effects in La0.67−x R x Sr0.33MnO3 (R=Eu, Gd)

Autor: V. V. Mashkautsan, N. G. Bebenin, R. I. Zainullina, V. G. Vasil’ev, B. V. Slobodin, V. V. Ustinov
Rok vydání: 2001
Předmět:
Zdroj: Physics of the Solid State. 43:501-507
ISSN: 1090-6460
1063-7834
DOI: 10.1134/1.1356128
Popis: An experimental study is reported on the temperature dependences of the magnetic susceptibility, electrical resistivity, magnetoresistance, thermo-and magnetothermopower, and on the Hall effect of the polycrystalline lanthanum manganites La0.67−x R x Sr0.33MnO3 (x=0 and 0.07, R=Eu, Gd) within the 77-to 430-K temperature range. Replacement of a small amount of lanthanum by europium or gadolinium was found to result in a considerable decrease in the resistivity and in a change in the pattern of its temperature dependence. The temperature dependence of both the ordinary and anomalous Hall coefficients near the Curie temperature is shown to be determined by the change in the number of carriers in delocalized states. A method is proposed for separation of the hole and electronic contributions to thermopower in the ferromagnetic region. The conduction mechanisms are discussed in terms of the concept of mobility edge motion.
Databáze: OpenAIRE
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