OPTICAL INVESTIGATIONS OF La0.7Ca0.3-xKxMnO3 (x = 0.00, 0.05 AND 0.10) PROBED BY SPECTROSCOPIC ELLIPSOMETRY

The optical properties of doped manganites in the paramagnetic state were studied by spectroscopic ellipsometry using polycrystalline La0.7Ca0.3-xKxMnO3 samples for (x = 0.00, 0.05 and 0.10) in the energy range of 3.2-5.5 eV at room temperature. The surface morphology of the samples was obtained by...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Ceramics (Praha) 2012-01, Vol.56 (2), p.95-101
Hauptverfasser: Sdiri, N, Boukhachem, A, Dhahri, E
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The optical properties of doped manganites in the paramagnetic state were studied by spectroscopic ellipsometry using polycrystalline La0.7Ca0.3-xKxMnO3 samples for (x = 0.00, 0.05 and 0.10) in the energy range of 3.2-5.5 eV at room temperature. The surface morphology of the samples was obtained by AFM. Refractive indices, extinction coefficients, and the transmission ellipsometric parameters Psi and Delta were investigated at different wavelengths. Analysis of the optical conductivity reveals that the optical behaviour and the activated transport in the paramagnetic state of these materials are consistent with Jahn-Teller small polaron effects. In addition, the spectrum of the complex dielectric constant reveals peaks for all samples; the results may be explained by the presence of space charges from the strongly dipole-allowed O(2p)-Mn(3d) transition.
ISSN:0862-5468
1804-5847