J. Phys. IV France
Volume 123, March 2005
Page(s) 193 - 196

J. Phys. IV France 123 (2005) 193-196

DOI: 10.1051/jp4:2005123033

Spectroscopy of Cr $^{\bf {3+}}$ in ferroelectric ceramics lead-lanthanum zirconate-titanate-x/95/5 with Lanthanum content x = 0.5 to 4 wt %

I. El-Harrad1, 2, C. Carabatos-Nédelec3 and A. Ridah2

1  Matériaux Micro-Optoélectroniques et Photonique, LOTEA, FSTE, BP. 509, Boutalamine, Errachidia, Maroc
2  Laboratoire de Contrôle et d'Analyse des Matérieux, Faculté des Sciences Ben Msik, BP. 7955, Casablanca, Maroc
3  Centre Lorrain d'Optique et Électronique des Solides, Université de Metz et Supélec, 2 rue E. Belin, Metz, France

The study shows the importance of internal optical transitions $^{2}{\rm E} \to^{4}$A2 of the excited Cr3+ ions used as a probe of the ceramics in the microscopic scale. The results are interpreted in terms of Cr3+ luminescent centres and simultaneous vibrational excitations of the lattice. In presence of thermally activated disorder, the PLZT-x/95/5 ferroelectric ceramics lead to interesting spectral variations with temperature by appearance of certain vibronic sidebands observed around the pure electronic transitions. The phononic origin of the process is analysed in terms of lattice perturbation in the environment of the Cr3+ sites.

© EDP Sciences 2005