| Autor: |
Loshkareva, N. N., Sukhorukov, Yu. P., Neifel’d, E. A., Arkhipov, V. E., Korolev, A. V., Gaviko, V. S., Panfilova, E. V., Dyakina, V. P., Mukovskiı, Ya. M., Shulyatev, D. A. |
| Předmět: |
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| Zdroj: |
Journal of Experimental & Theoretical Physics; Feb2000, Vol. 90 Issue 2, p389, 8p |
| Abstrakt: |
In order to study the microscopic nature of the phase separation in lanthanum manganites, experimental investigations were made of the optical, electrical, and magnetic properties of La[sub 1-δ]MnO[sub 3] and La[sub 0.9]Sr[sub 0.1]MnO[sub 3] lanthanum manganite single crystals. The infrared absorption spectra revealed two bands at 0.14 eV and 0.35 eV whose intensity was sensitive to the magnetic order. The different temperature dependence of the electrical resistivity (semiconducting) and the transmission (metallic) below the Curie ferromagnetic temperature indicates that an insulator-metal transition takes place in various regions of the insulating matrix, i.e., phase separation occurs. Characteristic features of the properties and the nature of the phase separation in these compounds can be explained using a model of polar (hole [MnO[sub 6, sup 8-]][sub JT] and electron [MnO[sub 6, sup 10-] ][sub JT]) pseudo-Jahn-Teller clusters which form centers of charge nonuniformity in the crystal. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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