STRUCTURAL, MAGNETIC AND ELECTRICAL PROPERTIES
S. Megdiche, A. Cheikh-Rouhou*
Laboratoire de Physique des Matériaux, Faculté des Sciences de Sfax,
B. P. 802, 3018 Sfax -Tunisie
* Corresponding Author. E-mail: Abdel.Cheikhrouhou@fss.rnu.tn
Receveid: 07 April 2001; revised version accepted 05 October 2001
A systematic study of the structural, magnetic and electrical properties of the diluted perovskite manganite oxides (La1-yPry)0.9Na0.1MnO3 (0.2 £ y £ 0.8) had been carried on. In this study, the average ionic radius <rA> of the A cation site was systematically varied while keeping fixed the carrier concentration (Mn3+/Mn4+ ratio). X-ray diffraction investigations showed a structural transition from the rhombohedral to the orthorhombic system for 0.33 < y < 0.5. The unit cell volume decreases with increasing Pr3+ content. Magnetic measurements showed that our synthesized samples exhibit a paramagnetic to ferromagnetic transition with decreasing temperature. Electrical measurements showed that all samples exhibited a semiconductor behavior in the whole temperature range 50-300 K.
Keywords : Perovskite ; Manganite; Resistivity; Magnetization.